PUBLISHED: APRIL 16, 2021

Comcast provides residential customers with a variety of high-speed broadband Internet access service plans from which to choose, with download speed tiers ranging from up to 50 megabits per second ("Mbps") to up to 1.2 gigabits per second ("Gbps") and upload speeds ranging from up to 5 Mbps to up to 35 Mbps on Comcast's DOCSIS hybrid fiber-coaxial ("HFC") network. Comcast also offers a fully fiber-based service with symmetrical download and upload speeds up to 2 Gbps. To see the plans currently available to you, please go to https://www.xfinity.com/learn/internet-service.

Comcast provisions its customers’ modems and gateways and engineers its network with the goal of enabling customers to enjoy the broadband Internet access service speeds to which they subscribe. Comcast also provides minimum system recommendations for each of the speed tiers it offers, which can be found at https://www.xfinity.com/support/internet/requirements-to-run-xfinity-internet-service/. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of broadband Internet access service to which a customer subscribes. As Comcast makes clear in its advertising and pricing information disclosures, "Actual speeds vary and are not guaranteed." The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of Comcast as an Internet Service Provider ("ISP).

THESE CONDITIONS INCLUDE:

1. Performance of a customer's computer, smartphone, tablet, or other Internet-connected device, including factors such as its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware, viruses and malware.
2. Type of connection between a customer's computer and router or gateway. For example, in-home wireless connections, e.g., Wi-Fi, between the device and the router or gateway generally may be slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference, attenuation, and congestion created by other devices in a customer’s home or neighborhood. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast’s services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast’s higher speed tiers. Customers can purchase an approved and compatible modem and router or gateway through a third-party retailer, or they can lease the necessary equipment from Comcast, though even wireless routers and gateways leased from Comcast are subject to some of the same limitations mentioned above. To achieve the best Wi-Fi performance and understand common Wi-Fi problems, please see this article on improving Wi-Fi performance. Where possible and where devices such as gaming consoles are in fixed locations, a wired Ethernet connection will usually provide better performance than Wi-Fi. If customers have poor Wi-Fi performance far from their access point, Wi-Fi extenders such as xFi Pods (aka mesh Wi-Fi systems) will usually improve performance – especially if those extenders use Ethernet to connect back to the gateway or access point (aka Ethernet backhaul).
3. The distance and time it takes for packets to travel between a customer’s modem/gateway and their final destination on the Internet, or their point of origination and a customer's modem/gateway, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks". A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks, as well as the capacity of the facilities the edge provider (i.e., any provider of content, applications, or services over the Internet) has chosen to route its traffic to Comcast’s network (and the interconnection capacity it has arranged), may affect the overall speed a customer experiences over their Internet connection.
4. Congestion or high usage levels at the edge provider or destination. When you access an edge provider or particular destination that is being visited by others at the same time, you may experience a slower connection if the edge provider or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the edge provider or destination. To control traffic or performance, many edge providers limit the speeds at which a visitor can download from their site. Those speed limitations will carry through to a customer’s connection.
6. The performance of the cable modem or gateway a customer has installed. Modem/gateway performance may degrade over time, and certain modems/gateways are not capable of handling higher speeds, such as DOCSIS 2.0 devices or early DOCSIS 3.0 devices. Comcast has a Device-to-Product Enforcement ("DPE") program to identify when customers may be using incompatible or old modem/gateway devices, whether leased or owned, that cannot support the speeds the customers subscribe to and provides instructions on how to obtain new modems/gateways capable of receiving the speeds and features included with their service. From time to time, Comcast may "end of life" certain cable modems/gateways or cease permitting those devices to attach to the network for network management and security reasons. Additionally, Comcast encourages its customers to promptly contact customer service if they have any concerns about their modem/gateway performance or speed capabilities. Please visit this page for information regarding cable modems/gateways approved for use on Comcast's network and to determine which devices can support various speeds.

Speed Measurements

The Federal Communications Commission ("FCC") conducts an ongoing, rigorous study of the performance of ISPs in the United States ("Measuring Broadband America"), including Comcast. The most recent report, the Tenth MBA Fixed Broadband Report dated January 4, 2021, from this study can be found on the FCC's website. The FCC determined that Comcast’s Xfinity Internet broadband Internet access services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, known as "peak" times, during sustained testing. Peak times are Monday through Friday from 7:00pm to 11:00pm local time.

The Detailed Measurement Results section below shows performance measurements by tier. While the general pattern of good performance reflected in the FCC's most recent Tenth FCC Measuring Broadband America report remains accurate, those measurements were collected between September and October 2019 and do not reflect currently offered service tier speeds. As a result, the information in the table below is based on data compiled by Comcast using a largely similar testing methodology.

Latency Measurements

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience. Comcast has no basis for stating what level of latency should be expected by any particular user at any particular time but notes that latency on its own is usually a reflection of the physical type of access network, as noted in the FCC's Measuring Broadband America study.

The FCC's Measuring Broadband America study measures latency using tests that calculate the time it takes for packets to travel from a customer location to a target test node and back. On speed tiers not covered by the Measuring Broadband America study, in tests conducted by Comcast, the test nodes are located in the Comcast network.

These results do not define latency as part of a particular user experience because:

1. The results from the FCC study include time spent traversing networks not controlled by Comcast; and
2. The geographic distance between any given user and the target node used in the Comcast test may vary greatly from those employed in the FCC study.

Customers can test the latency characteristics of their service using the xFi app or web-based Xfinity speed test noted below. Other latency tests may also be available on the Internet. Of course, other than for the test to the cable modem gateway, these tests will reflect limitations in a customer's home network (especially Wi-Fi) and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

Detailed Measurement Results

When reading these results, each row represents a specific service tier with its respective advertised downstream and upstream speed. For example, the first row represents Comcast's 50/5 Mbps service tier.

The tiers listed in the table below are limited to those currently available for purchase as of March 15, 2021, and tiers that have been retired as an offering but that a substantial number of customers have retained for the time being. This table may include service tiers that are not available in all markets. The measurements with notation (1) are derived from tests to the cable modem gateway collected from 1/1/2021 – 3/1/2021. The measurements with notation (2) are derived from tests to the cable modem gateway collected from 3/1/2021 – 3/14/2021, a more recent period used because these new speed tiers only became available in March 2021. Notation (3) is for measurements conducted for Comcast’s dedicated fiber service.

Download Speed Tier (Mbps)	Download Speed: Median at Peak (Mbps)	Download Speed: Median - Off-Peak (Mbps)	Upload Speed Tier (Mbps)	Upload Speed: Median at Peak (Mbps)	Upload Speed: Median - Off-Peak (Mbps)	Latency: Median at Peak (ms)	Latency: Median - Off-Peak (ms)	Notation
50	58.4	58.8	5	5.8	5.9	20	19	2
70	82.2	82.3	5	5.9	5.9	16	16	1
100	117.5	117.6	5	5.9	5.9	19	18	1
175	205.6	205.8	5	5.9	5.9	18	17	1
200	234.8	235.2	5	5.9	5.9	19	18	1
200	235.1	235.3	10	11.7	11.7	19	18	1
275	322.9	323.3	10	11.7	11.7	17	16	1
400	466.3	469.3	10	11.7	11.7	15	15	1
500	585.4	587.0	15	17.6	17.6	13	13	1
600	698.8	703.1	15	17.5	17.6	15	15	1
800	638.5	676.1	15	17.5	17.5	19	19	2
800	697.1	730.6	20	23.4	23.4	18	17	2
1,200	1,260	1,338	35	40.7	40.8	15	15	1
2,000	2,086	2,060	2,000	2,088	2,065	13	13	3
(1)Based on tests to the cable modem gateway collected from 1/1/2021 – 3/1/2021.			(2)Based on tests to the cable modem gateway collected from 3/1/2021 – 3/14/2021, a more recent period used because these new speed tiers only became available in March 2021.			(3)Based on measurements conducted for Comcast’s dedicated fiber service.

As the results demonstrate, Comcast's Xfinity Internet broadband Internet access services deliver over 100 percent of their advertised downstream and upstream speeds during both peak and off-peak times. While individual experiences may vary, the FCC's and Comcast's tests consistently confirm the delivery quality of Comcast's Xfinity Internet broadband Internet access services.

Comcast's fastest DOCSIS-based download speed is currently 1.2 Gbps and fiber-based is 2 Gbps. But individual customer devices likely will experience speeds lower than this due to the technological limitations of 1 Gigabit Ethernet ports, which are not specific to Comcast’s network. However, multiple devices simultaneously connected to the cable modem gateway can push aggregate usage up to the advertised 1.2 Gbps rate.

Consumers can also test their speeds themselves. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast’s network using either the xFi app or via a web browser. These tests enable customers, depending on their equipment, to test the speed to their cable modem gateway as well as from their device on the home’s local area network to test sites located throughout Comcast’s network. The test from a customer device can be run in three ways:

1. Via the Xfinity website, or
2. For the app-based gateway test, by using the xFi app. To conduct the gateway test, in the xFi app, select Connect, then Internet Health, and then Test Speed to Gateway.
3. For the app-based test, by using the xFi app. To conduct the device test, in the xFi app, select Connect, then Internet Health, and then Test Speed to Device.

There are other speed tests available that measure Internet performance as well. We have provided links to a few of these sites below for your reference. Please note, however, that speed tests that originate from a consumer device on the customer's home local area network (not a gateway or modem) have limitations and flaws and some of them have difficulty measuring multi-hundred megabit per second or gigabit per second service tiers, among other potential issues. Each of these tests measure limited aspects of an ISP's performance and therefore must be seen as a guide rather than a definitive measurement of the performance of the Comcast network.

• https://www.speedtest.net/
• https://fast.com/
• https://speedof.me/

XFINITY WiFi Hotspots

In addition to the residential or commercial broadband Internet access service that you enjoy at your home or office, Comcast provides eligible subscribers and other consumers with access to Xfinity WiFi hotspots, which allows those users to access the Internet when they are at one of the many Xfinity WiFi or Cable WiFi hotspots. Comcast engineers the network underlying Xfinity WiFi hotspots to deliver high-performance access to the Internet. However, the performance you experience once you connect to an Xfinity WiFi hotspot may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your WiFi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many other factors beyond Comcast’s control. These hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that Comcast's use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided solely on a "best efforts" basis.

PUBLISHED: AUGUST 19, 2019

Comcast provides residential customers with a variety of high-speed broadband Internet access service plans from which to choose, with download speed tiers ranging from up to 5 megabits per second ("Mbps") to up to 1 gigabit per second and upload speeds ranging from up to 768 kilobits per second ("Kbps") to up to 35 Mbps on our DOCSIS 3.0 and 3.1 cable networks. We also offer a fiber-based service with symmetrical download and upload speeds up to 2 Gbps. To see the plans currently available to you, please go to https://www.xfinity.com/learn/internet-service.

Comcast provisions its customers' modems and gateways and engineers its network with the goal of enabling customers to enjoy the broadband Internet access service speeds to which they subscribe. Comcast also provides minimum system recommendations for each of the speed tiers it offers, which can be found at https://www.xfinity.com/support/internet/requirements-to-run-xfinity-internet-service/. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of broadband Internet access service to which a customer subscribes. As Comcast makes clear in its advertising and pricing information disclosures, "Actual speeds vary and are not guaranteed." The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of Comcast as an Internet Service Provider ("ISP").

THESE CONDITIONS INCLUDE:

1. Performance of a customer's computer, smartphone, tablet, or other Internet-connected device, including factors such as its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections, e.g., WiFi, between the device and the router or modem generally may be slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference, attenuation, and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to some of the same limitations mentioned above.
3. The distance and time it takes packets to travel between a customer's modem and their final destination on the Internet, or their point of origination and a customer's modem, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks, as well as the capacity of the facilities the edge provider (i.e., any provider of content, applications, or services over the Internet) has chosen to route its traffic to Comcast's network (and the interconnection capacity it has arranged), may affect the overall speed of an Internet connection.
4. Congestion or high usage levels at the edge provider or destination. When you access an edge provider or particular destination that is being visited by others at the same time, you may experience a slower connection if the edge provider or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the edge provider or destination. To control traffic or performance, many edge providers limit the speeds at which a visitor can download from their site. Those speed limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds, such as DOCSIS 2.0 devices or early DOCSIS 3.0 devices. Comcast has a Device-to-Product Enforcement ("DPE") program to identify when customers may be using incompatible or old modem devices, whether leased or owned, and provides instructions on how to obtain new modems capable of receiving the speeds and features included with their service. From time to time Comcast may “end of life” certain cable modems or cease permitting those devices to attach to the network for network management and security reasons. Additionally, Comcast encourages its customers to promptly contact customer service if they have any concerns about their modem performance or speed capabilities. Please visit My Device Info for information regarding cable modems approved for use on Comcast's network and to determine which devices can support various speeds.

Speed

The Federal Communications Commission ("FCC") conducts an ongoing, rigorous study of the performance of ISPs in the United States ("Measuring Broadband America"), including Comcast. The most recent report from this study can be found on the FCC's website. The FCC determined that Comcast's Xfinity Internet broadband Internet access services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, known as "peak" times, during sustained testing. Peak times are Monday through Friday from 7:00pm to 11:00pm local time.

Below are the median download and upload speeds by tier. Unless otherwise noted, the reported information comes from the latest FCC study. Certain service tiers noted below were not included in the FCC's study either because they are newer products with limited availability or they do not meet the study's reporting requirements. For these noted tiers, the information below is based on data compiled independently by Comcast during the same time period as the FCC study and using a largely similar testing methodology.

Download Speed Tier	Measured Speed (Peak)	Upload Speed Tier	Measured Speed (Peak)
5 Mbps	5.95 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	2 Mbps	2.4 Mbps(1)
25 Mbps	29.41 Mbps	0.768 Mbps	0.89 Mbps(1)
50 Mbps	57.56 Mbps(1)	5 Mbps	5.92 Mbps
75 Mbps	83.11 Mbps	10 Mbps	11.89 Mbps
100 Mbps	111.07 Mbps	5 Mbps	5.92 Mbps
150 Mbps	151.65 Mbps(1)	20 Mbps	23.73 Mbps(1)
200 Mbps	221.07 Mbps(1)	10 Mbps	11.89 Mbps(1)
250 Mbps	265.1 Mbps(1)	25 Mbps	29.7 Mbps(1)
300 Mbps	318.2 Mbps(1)	25 Mbps	29.7 Mbps(1)
1 Gbps(2)	931.51 Mbps(1)(3)	35 Mbps(2)	38.25 Mbps(1)
2 Gbps	2,086 Mbps(1)	2 Gbps	2,060 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Available in most, but not all, markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

Comcast's Xfinity Internet broadband Internet access services also deliver over 100 percent of their advertised downstream and upstream speeds during periods of time when Internet usage is generally lighter, known as "off peak" times, during sustained testing.

COMCAST MEDIAN SPEEDS BY TIER DURING OFF PEAK TIMES:

Download Speed (Off Peak)	Measured Speed	Upload Speed (Off Peak)	Measured Speed
5 Mbps	5.95 Mbps(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mbps(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mbps(1)	2 Mbps	2.4 Mpbs(1)
25 Mbps	29.51 Mbps	0.768 Mbps	0.90 Mpbs
50 Mbps	58.59 Mbps	5 Mbps	5.93 Mpbs
75 Mbps	86.02 Mbps	10 Mbps	11.89 Mpbs
100 Mbps	113.01 Mbps	5 Mbps	5.93 Mpbs
150 Mbps	168.29 Mbps(1)	20 Mbps	23.75 Mbps(1)
200 Mbps	230.83 Mbps(1)	10 Mbps	11.89 Mpbs(1)
250 Mbps	292.5 Mbps(1)	25 Mbps	29.9 Mpbs(1)
300 Mbps	336.5 Mbps(1)	25 Mbps	29.9 Mpbs(1)
1 Gbps(2)	941.03 Mbps(1)(3)	35 Mbps(2)	41.73 Mbps(1)
2 Gbps	2,088 Mbps(1)	2 Gbps	2,065 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Available in most, but not all, markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

While individual experiences may vary, the FCC's and Comcast’s tests have consistently confirmed the quality of Comcast's Xfinity Internet broadband Internet access services.

You also can test your speeds yourself. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast's network from the customer's computer to test sites located throughout Comcast's network. Simply go to Xfinity Speed Test to test your connection. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

There are other speed tests that measure Internet performance. We have provided links to a few of these sites below for your reference. Please note, however, that all speed tests have limitations and flaws. Each of these tests measures limited aspects of an ISP's speed and therefore must be seen as a guide rather than definitive measurements of performance.

• https://www.speedtest.net/
• https://fast.com/
• https://speedof.me/

Latency

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience. Comcast has no basis for saying what level of latency should be expected by any particular user at any particular time but notes that the measured results from the FCC study as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

The FCC study measures latency using packet tests that calculate the time it takes for packets to travel from a customer location to a target test node and back. Below are the Comcast median latency results by tier during peak times (as defined above), during sustained testing:

Speed Tier	Latency (Peak)
Down 5 Mbps	12.3 ms(1)
Down 10 Mbps	16.4 ms(1)
Down 25 Mbps	20.44 ms
Down 50 Mbps	25.20 ms
Down 75 Mbps	22.62 ms
Down 100 Mbps	20.52 ms
Down 150 Mbps	19.20 ms(1)
Down 200 Mbps	21.07 ms(1)
Down 250 Mbps	24.3 ms(1)
Down 300 Mbps	39.1 ms(1)
Down 1 Gbps	15.2 ms(1)
Down 2 Gbps	12.8 ms(1)
(1)Based on measurements by Comcast

Below are the Comcast median latency results by tier during off peak times, during sustained testing:

Speed Tier	Latency (Off Peak)
Down 5 Mbps	11.7 ms(1)
Down 10 Mbps	13.7 ms(1)
Down 25 Mbps	19.86 ms
Down 50 Mbps	24.96 ms(1)
Down 75 Mbps	22.15 ms
Down 100 Mbps	20.26 ms
Down 150 Mbps	18.75 ms
Down 200 Mbps	20.71 ms(1)
Down 250 Mbps	23.2 ms(1)
Down 300 Mbps	37.3 ms(1)
Down 1 Gbps	14 ms(1)
Down 2 Gbps	12.6 ms(1)
(1)Based on measurements by Comcast

These results do not define latency as part of a particular user experience because:

1. The results include time spent traversing networks not controlled by Comcast;
2. The geographic distance between any given user and the target node may vary greatly from those employed in the FCC study.

Customers can test the latency characteristics of their service at Xfinity Speed Test. Of course, this test also may reflect limitations in a customer's home network (especially WiFi) and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

There are other latency tests available on the Internet. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance.

XFINITY WiFi Hotspots

In addition to the residential or commercial broadband Internet access service that you enjoy at your home or office, Comcast provides eligible subscribers and other consumers with access to Xfinity WiFi hotspots, which allow eligible subscribers and other consumers to access the Internet when they are at one of the many Xfinity WiFi or Cable WiFi hotspots. Comcast engineers the network underlying Xfinity WiFi hotspots to deliver high-performance access to the Internet. However, the performance you experience once you connect to an Xfinity WiFi hotspot may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your WiFi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many other factors beyond Comcast’s control. These hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that our use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided solely on a "best efforts" basis.

PUBLISHED: JUNE 11, 2018

Comcast provides residential customers with a variety of high-speed broadband Internet access service plans from which to choose, with download speed tiers ranging from up to 5 megabits per second ("Mbps") to up to 1 gigabit per second and upload speeds ranging from up to 768 kilobits per second ("Kbps") to up to 35 Mbps on our DOCSIS 3.0 and 3.1 cable networks. We also offer a fiber-based service with symmetrical download and upload speeds up to 2 Gbps. To see the plans currently available to you, please go to https://www.xfinity.com/learn/internet-service.

Comcast provisions its customers' modems and gateways and engineers its network with the goal of enabling customers to enjoy the broadband Internet access service speeds to which they subscribe. Comcast also provides minimum system recommendations for each of the speed tiers it offers, which can be found at https://www.xfinity.com/support/internet/requirements-to-run-xfinity-internet-service/. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of broadband Internet access service to which a customer subscribes. As Comcast makes clear in its advertising and pricing information disclosures, "Actual speeds vary and are not guaranteed." The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of Comcast as an Internet Service Provider ("ISP").

THESE CONDITIONS INCLUDE:

1. Performance of a customer's computer, smartphone, tablet, or other Internet-connected device, including factors such as its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections, e.g., Wi-Fi, between the device and the router or modem generally may be slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference, attenuation, and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to some of the same limitations mentioned above.
3. The distance and time it takes packets to travel between a customer's modem and their final destination on the Internet, or their point of origination and a customer's modem, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks, as well as the capacity of the facilities the edge provider (i.e., any provider of content, applications, or services over the Internet) has chosen to route its traffic to Comcast's network (and the interconnection capacity it has arranged), may affect the overall speed of an Internet connection.
4. Congestion or high usage levels at the edge provider or destination. When you access an edge provider or particular destination that is being visited by others at the same time, you may experience a slower connection if the edge provider or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the edge provider or destination. To control traffic or performance, many edge providers limit the speeds at which a visitor can download from their site. Those speed limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds, such as DOCSIS 2.0 devices or early DOCSIS 3.0 devices. Comcast has a Device-to-Product Enforcement ("DPE") program to identify when customers may be using incompatible or old modem devices, whether leased or owned, and provides instructions on how to obtain new modems capable of receiving the speeds and features included with their service. From time to time Comcast may “end of life” certain cable modems or cease permitting those devices to attach to the network for network management and security reasons. Additionally, Comcast encourages its customers to promptly contact customer service if they have any concerns about their modem performance or speed capabilities. Please visit My Device Info for information regarding cable modems approved for use on Comcast's network and to determine which devices can support various speeds.

Speed

The Federal Communications Commission ("FCC") conducts an ongoing, rigorous study of the performance of ISPs in the United States ("Measuring Broadband America"), including Comcast. The most recent report from this study can be found on the FCC's website. The FCC determined that Comcast's XFINITY Internet broadband Internet access services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, known as "peak" times, during sustained testing. Peak times are Monday through Friday from 7:00pm to 11:00pm local time.

Below are the median download and upload speeds by tier. Unless otherwise noted, the reported information comes from the latest FCC study. We are including the FCC's measurement of the 105 Mbps speed tier, which we no longer offer, on an interim basis until the FCC releases its next Measuring Broadband America report, which is expected to include measurement of the 100 Mbps speed tier, but we do not expect the results to differ significantly. Certain service tiers noted below were not included in the FCC's study either because they are newer products with limited availability or they do not meet the study's reporting requirements. For these noted tiers, the information below is based on data compiled independently by Comcast during the same time period as the FCC study and using a largely similar testing methodology.

Download Speed Tier	Measured Speed (Peak)	Upload Speed Tier	Measured Speed (Peak)
5 Mbps	5.95 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	2 Mbps	2.4 Mbps(1)
25 Mbps	28.90 Mbps	0.768 Mbps	0.89 Mbps
50 Mbps	57.56 Mbps	5 Mbps	5.91 Mbps
75 Mbps	85.38 Mbps	10 Mbps	11.87 Mbps
105 Mbps	110.81 Mbps	5 Mbps	5.91 Mbps
150 Mbps	151.65 Mbps(1)	20 Mbps	22.1 Mbps(1)
200 Mbps	212.2 Mbps(1)	10 Mbps	11.5 Mbps(1)
250 Mbps	265.1 Mbps(1)	25 Mbps	29.7 Mbps(1)
300 Mbps	318.2 Mbps(1)	25 Mbps	29.7 Mbps(1)
1 Gbps(2)	931.51 Mbps(1)(3)	35 Mbps(2)	38.25 Mbps(1)
2 Gbps	2,086 Mbps(1)	2 Gbps	2,060 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Available in most, but not all, markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

Comcast's XFINITY Internet broadband Internet access services also deliver over 100 percent of their advertised downstream and upstream speeds during periods of time when Internet usage is generally lighter, known as "off peak" times, during sustained testing.

COMCAST MEDIAN SPEEDS BY TIER DURING OFF PEAK TIMES:

Download Speed (Off Peak)	Measured Speed	Upload Speed (Off Peak)	Measured Speed
5 Mbps	5.95 Mpbs(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mpbs(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mpbs(1)	2 Mbps	2.4 Mpbs(1)
25 Mbps	29.36 Mpbs	0.768 Mbps	0.90 Mpbs
50 Mbps	58.59 Mpbs	5 Mbps	5.93 Mpbs
75 Mbps	88.61 Mpbs	10 Mbps	11.89 Mpbs
105 Mbps	120.05 Mpbs	5 Mbps	5.93 Mpbs
150 Mbps	168.29 Mpbs(1)	20 Mbps	22.58 Mbps(1)
200 Mbps	224.3 Mpbs(1)	10 Mbps	11.7 Mpbs(1)
250 Mbps	292.5 Mpbs(1)	25 Mbps	29.9 Mpbs(1)
300 Mbps	336.5 Mpbs(1)	25 Mbps	29.9 Mpbs(1)
1 Gbps(2)	941.03 Mbps(1)(3)	35 Mbps(2)	41.73 Mbps(1)
2 Gbps	2,088 Mbps(1)	2 Gbps	2,065 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Available in most, but not all, markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

While individual experiences may vary, the FCC's and Comcast’s tests have consistently confirmed the quality of Comcast's XFINITY Internet broadband Internet access services.

You also can test your speeds yourself. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast's network from the customer's computer to test sites located throughout Comcast's network. Simply go to XFINITY Speed Test to test your connection. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

There are other speed tests that measure Internet performance. We have provided links to a few of these sites below for your reference. Please note, however, that all speed tests have limitations and flaws. Each of these tests measures limited aspects of an ISP's speed and therefore must be seen as a guide rather than definitive measurements of performance.

• http://www.speedtest.net
• http://netalyzr.icsi.berkeley.edu

 

Latency

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience. Comcast has no basis for saying what level of latency should be expected by any particular user at any particular time but notes that the measured results from the FCC study as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

The FCC study measures latency using packet tests that calculate the time it takes for packets to travel from a customer location to a target test node and back. Below are the Comcast median latency results by tier during peak times (as defined above), during sustained testing:

Speed Tier	Latency (Peak)
Down 5 Mbps	12.3 ms(1)
Down 10 Mbps	16.4 ms(1)
Down 25 Mbps	20.90 ms
Down 50 Mbps	25.20 ms
Down 75 Mbps	18.74 ms
Down 105 Mbps	23.98 ms
Down 150 Mbps	19.20 ms
Down 200 Mbps	19.7 ms(1)
Down 250 Mbps	24.3 ms(1)
Down 300 Mbps	39.1 ms(1)
Down 1 Gbps	15.2 ms(1)
Down 2 Gbps	12.8 ms(1)
(1)Based on measurements by Comcast

Below are the Comcast median latency results by tier during off peak times, during sustained testing:

Speed Tier	Latency (Off Peak)
Down 5 Mbps	11.7 ms(1)
Down 10 Mbps	13.7 ms(1)
Down 25 Mbps	19.83 ms
Down 50 Mbps	24.96 ms
Down 75 Mbps	18.46 ms
Down 105 Mbps	23.67 ms
Down 150 Mbps	18.75 ms
Down 200 Mbps	20.2 ms(1)
Down 250 Mbps	23.2 ms(1)
Down 300 Mbps	37.3 ms(1)
Down 1 Gbps	14 ms(1)
Down 2 Gbps	12.6 ms(1)
(1)Based on measurements by Comcast

These results do not define latency as part of a particular user experience because:

1. The results include time spent traversing networks not controlled by Comcast;
2. The geographic distance between any given user and the target node may vary greatly from those employed in the FCC study.

Customers can test the latency characteristics of their service at XFINITY Speed Test. Of course, this test also may reflect limitations in a customer's home network (especially Wi-Fi) and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

There are other latency tests available on the Internet. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance.

XFINITY WiFi Hotspots

In addition to the residential or commercial broadband Internet access service that you enjoy at your home or office, Comcast provides its broadband Internet access service subscribers with access to XFINITY WiFi hotspots, which allow XFINITY Internet subscribers to access the Internet when they are at one of the many XFINITY WiFi or Cable WiFi hotspots. Comcast engineers the network underlying XFINITY WiFi hotspots to deliver high-performance access to the Internet. However, the performance you experience once you connect to an XFINITY WiFi hotspot may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your Wi-Fi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many other factors beyond Comcast’s control. These hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that our use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided solely on a "best efforts" basis.

PUBLISHED: JUNE 11, 2018

Following the deployment of DOCSIS 3.1 technology in our network, we have updated our DOCSIS Cable Modem Process and Requirements.

PUBLISHED: JUNE 11, 2018

As reflected in a June 11, 2018 update to our XFINITY Internet Broadband Disclosures, the congestion management system that was initially deployed in 2008 has been deactivated. As our network technologies and usage of the network continue to evolve, we reserve the right to implement a new congestion management system if necessary in the performance of reasonable network management and in order to maintain a good broadband Internet access service experience for our customers, and will provide updates here as well as other locations if a new system is implemented.

PUBLISHED: AUGUST 4, 2017

Comcast provides residential customers with a variety of high-speed Internet plans from which to choose, with download speed tiers ranging from up to 5 megabits per second ("Mbps") to up to 1 gigabit per second in select markets and upload speeds ranging from up to 768 kilobits per second ("Kbps") to up to 35 Mbps on our DOCSIS 3.0 and 3.1 cable networks. We also offer a fiber-based service with symmetrical download and upload speeds up to 2 Gbps. To see the plans currently available to you, please go to https://www.xfinity.com/learn/internet-service.

Comcast provisions its customers' modems and engineers its network with the goal of enabling customers to enjoy the speeds to which they subscribe. Comcast also provides minimum system recommendations for each of the speed tiers it offers, which can be found at https://www.xfinity.com/support/internet/requirements-to-run-xfinity-internet-service/. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of service to which a customer subscribes. As Comcast makes clear in its advertising and pricing information disclosures, "Actual speeds vary and are not guaranteed." The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of Comcast as an Internet Service Provider ("ISP").

THESE CONDITIONS INCLUDE:

1. Performance of a customer's computer, including factors such as its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections between the computer and the router or modem may be generally slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference, attenuation, and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to some of the same limitations mentioned above.
3. The distance and time it takes packets to travel between a customer's modem and their final destination on the Internet, or their point of origination and a customer's modem, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks, as well as the capacity of the facilities the edge provider (i.e., any provider of content, applications, or services over the Internet) has chosen to route its traffic to Comcast's network (and the interconnection capacity it has arranged), may affect the overall speed of an Internet connection.
4. Congestion or high usage levels at the edge provider or destination. When you access an edge provider or particular destination that is being visited by others at the same time, you may experience a slower connection if the edge provider or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the edge provider or destination. To control traffic or performance, many edge providers limit the speeds at which a visitor can download from their site. Those speed limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds, such as DOCSIS 2.0 devices or early DOCSIS 3.0 devices. Comcast has a Device-to-Product Enforcement ("DPE") program to identify when customers may be using incompatible or old modem devices, whether leased or owned, and provides instructions on how to obtain new modems capable of receiving the speeds and features included with their service. Additionally, Comcast encourages its customers to promptly contact customer service if they have any concerns about their modem performance or speed capabilities. Please visit My Device Info for information regarding cable modems approved for use on Comcast's network and to determine which devices can support various speeds.

Speed

The Federal Communications Commission ("FCC") conducts an ongoing, rigorous study of the performance of the largest ISPs in the United States ("Measuring Broadband America"), including Comcast. The most recent report from this study can be found on the FCC's website. The FCC determined that Comcast's Xfinity Internet services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, known as "peak" times, during sustained testing. Peak times are Monday through Friday from 7:00pm to 11:00pm local time.

Below are the median download and upload speeds by tier. Unless otherwise noted, the reported information comes from the latest FCC study. We are including the FCC's measurement of the 105 Mbps speed tier, which we no longer offer, on an interim basis until internal measurements of our 100 Mbps speed tier are completed, but we do not expect the results to differ significantly. Service tiers noted below were not included in the FCC's study either because they are newer products with limited availability or they do not meet the study's reporting requirements. For these noted tiers, the information below is based on data compiled independently by Comcast during the same time period as the FCC study and using a largely similar testing methodology.

Download Speed Tier	Measured Speed (Peak)	Upload Speed Tier	Measured Speed (Peak)
5 Mbps	5.95 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	1 Mbps	1.21 Mbps(1)
10 Mbps	11.8 Mbps(1)	2 Mbps	2.4 Mbps(1)
25 Mbps	28.90 Mbps	0.768 Mbps	0.89 Mbps
50 Mbps	57.56 Mbps	5 Mbps	5.91 Mbps
75 Mbps	85.38 Mbps	10 Mbps	11.87 Mbps
105 Mbps	110.81 Mbps	5 Mbps	5.91 Mbps
150 Mbps	151.65 Mbps(1)	20 Mbps	22.1 Mbps(1)
200 Mbps	212.2 Mbps(1)	10 Mbps	11.5 Mbps(1)
250 Mbps	265.1 Mbps(1)	25 Mbps	29.7 Mbps(1)
300 Mbps	318.2 Mbps(1)	25 Mbps	29.7 Mbps(1)
1 Gbps(2)	931.51 Mbps(1)(3)	35 Mbps(2)	38.25 Mbps(1)
2 Gbps	2,086 Mbps(1)	2 Gbps	2,060 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Only available in select markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

Comcast's Xfinity Internet services also deliver over 100 percent of their advertised downstream and upstream speeds during periods of time when Internet usage is generally lighter, known as "off peak" times, during sustained testing.

COMCAST MEDIAN SPEEDS BY TIER DURING OFF PEAK TIMES:

Download Speed (Off Peak)	Measured Speed	Upload Speed (Off Peak)	Measured Speed
5 Mbps	5.95 Mpbs(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mpbs(1)	1 Mbps	1.21 Mpbs(1)
10 Mbps	11.8 Mpbs(1)	2 Mbps	2.4 Mpbs(1)
25 Mbps	29.36 Mpbs	0.768 Mbps	0.90 Mpbs
50 Mbps	58.59 Mpbs	5 Mbps	5.93 Mpbs
75 Mbps	88.61 Mpbs	10 Mbps	11.89 Mpbs
105 Mbps	120.05 Mpbs	5 Mbps	5.93 Mpbs
150 Mbps	168.29 Mpbs(1)	20 Mbps	22.58 Mbps(1)
200 Mbps	224.3 Mpbs(1)	10 Mbps	11.7 Mpbs(1)
250 Mbps	292.5 Mpbs(1)	25 Mbps	29.9 Mpbs(1)
300 Mbps	336.5 Mpbs(1)	25 Mbps	29.9 Mpbs(1)
1 Gbps(2)	941.03 Mbps(1)(3)	35 Mbps(2)	41.73 Mbps(1)
2 Gbps	2,088 Mbps(1)	2 Gbps	2,065 Mbps(1)
(1)Based on independent measurements by Comcast		(2)Only available in select markets
(3)Due to current technological limitations related to the capabilities of Ethernet ports in current hardware, download speeds through those ports for 1 Gbps service are limited as specified in the table above.

While individual experiences may vary, the FCC's tests have consistently confirmed the quality of Comcast's Xfinity Internet services.

You also can test your speeds yourself. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast's network from the customer's computer to test sites located throughout Comcast's network. Simply go to Xfinity Speed Test to test your connection. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

There are other speed tests that measure Internet performance. We have provided links to a few of these sites below for your reference. Please note, however, that all speed tests have limitations and flaws. Each of these tests measures limited aspects of an ISP's speed and therefore must be seen as a guide rather than definitive measurements of performance.

• http://www.speedtest.net
• http://netalyzr.icsi.berkeley.edu

 

Latency

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience. Comcast has no basis for saying what level of latency should be expected by any particular user at any particular time but notes that the measured results from the FCC study as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

The FCC study measures latency using packet tests that calculate the time it takes for packets to travel from a customer location to a target test node and back. Below are the Comcast median latency results by tier during peak times (as defined above), during sustained testing:

Speed Tier	Latency (Peak)
Down 5 Mbps	12.3 ms(1)
Down 10 Mbps	16.4 ms(1)
Down 25 Mbps	20.90 ms
Down 50 Mbps	25.20 ms
Down 75 Mbps	18.74 ms
Down 105 Mbps	23.98 ms
Down 150 Mbps	19.20 ms
Down 200 Mbps	19.7 ms(1)
Down 250 Mbps	24.3 ms(1)
Down 300 Mbps	39.1 ms(1)
Down 1 Gbps	15.2 ms(1)
Down 2 Gbps	12.8 ms(1)
(1)Based on measurements by Comcast

Below are the Comcast median latency results by tier during off peak times, during sustained testing:

Speed Tier	Latency (Off Peak)
Down 5 Mbps	11.7 ms(1)
Down 10 Mbps	13.7 ms(1)
Down 25 Mbps	19.83 ms
Down 50 Mbps	24.96 ms
Down 75 Mbps	18.46 ms
Down 105 Mbps	23.67 ms
Down 150 Mbps	18.75 ms
Down 200 Mbps	20.2 ms(1)
Down 250 Mbps	23.2 ms(1)
Down 300 Mbps	37.3 ms(1)
Down 1 Gbps	14 ms(1)
Down 2 Gbps	12.6 ms(1)
(1)Based on measurements by Comcast

These results do not define latency as part of a particular user experience because:

1. The results include time spent traversing networks not controlled by Comcast;
2. The geographic distance between any given user and the target node may vary greatly from those employed in the FCC study.

Customers can test the latency characteristics of their service at Xfinity Speed Test. Of course, this test also may reflect limitations in a customer's home network (especially Wi-Fi) and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

There are other latency tests available on the Internet. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance.

Packet Loss

Packet loss is a third measurement of Internet performance. Packet loss is the percentage of packets that are sent by the source but not received by the destination. This is sometimes due to congestion along the route but may also reflect an impairment in a customer's home network, including their Wi-Fi and coaxial cable network as well as the connection from the customer's home to the Comcast network. Customers should diagnose their home network for possible repair if packet loss is high. Packet loss is also a normal part of the Transmission Control Protocol (TCP), and signals to a sender to slow their sending rate to adjust to available bandwidth along a network path. As a result, a small amount of packet loss is expected and normal, but it is unlikely to directly affect the perceived quality of applications that request retransmission of lost packets, such as web browsing and email. In addition, measures to further reduce packet loss would require unacceptable increases in latency. However, packet loss may affect the perceived quality of applications that do not request retransmission of lost packets, such as VoIP phone calls and video chat. Nevertheless, packet losses of a few tenths of a percent are sufficiently small so that they are unlikely to significantly affect the perceived quality of these applications. The Internet's technical community continues to debate the merit and meaning of packet loss measurement. Comcast has no basis for saying what level of packet loss should be expected by any particular user at any particular time but notes that the measured results from the FCC study as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

The FCC study includes packet loss tests performed using packet tests that measure the time it takes those packets to travel from a customer location to a target test node and back. Packets not received back within three seconds of sending were treated as lost. Below are the Comcast average packet loss results by tier during peak times (as defined above), during sustained testing. Comcast currently does not have packet loss data for our 5, 10, 200, 250, 300 Mbps and 1 Gbps services tiers. However, based on data from the latest FCC study, we expect packet loss to be in the range of 0.08% to 0.19%.

Speed Tier	Packet Loss (Peak)
Down 25 Mbps	0.10%
Down 50 Mbps	0.08%
Down 75 Mbps	0.10%
Down 105 Mbps	0.06%
Down 150 Mbps	0.10%
Down 2 Gbps	0.19%(1)
(1)Based on measurements by Comcast

Below are the Comcast average packet loss results by tier during off peak times, during sustained testing. Comcast currently does not have packet loss data for our 5, 10, 200, 250, 300 Mbps and 1 Gbps services tiers. However, based data from the FCC study, we expect packet loss to be in the range of 0.06% to 0.17%.

Speed Tier	Packet Loss (Off Peak)
Down 25 Mbps	0.06%
Down 50 Mbps	0.10%
Down 75 Mbps	0.07%
Down 105 Mbps	0.07%
Down 150 Mbps	0.07%
Down 2 Gbps	0.17%(1)
(1)Based on measurements by Comcast

Customers can test their packet loss by performing ping tests or other tests. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

Xfinity WiFi

In addition to the residential or commercial Internet service that you enjoy at your home or office, Comcast provides its Internet subscribers with Xfinity WiFi, which allows Xfinity Internet subscribers to access the Internet when they are at one of the many Xfinity or Cable WiFi hotspots. Comcast engineers the underlying network to deliver high-performance access to the Internet. However, the performance you experience, once you connect to the hotspot, may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your Wi-Fi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many of the factors already mentioned above. These Wi-Fi hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that our use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided solely on a "best efforts" basis.

PUBLISHED: JANUARY 19, 2017

At Comcast, we periodically review and revise our website to ensure that customers have the latest information about our services. We have revised our Internet service performance webpage to give customers the latest information to help them make informed choices.

Comcast provides residential customers with a variety of high-speed Internet plans from which to choose, with download speed tiers ranging from up to 5 megabits per second (" Mbps") to up to 300 Mbps (in select markets) and upload speeds ranging from up to 768 kilobits per second ("Kbps") to up to 25 Mbps on our DOCSIS 3.0 and 3.1 cable networks. In select markets, we also offer a fiber-based service with symmetrical download and upload speeds up to 2 gigabits per second ("Gbps"). To see the plans currently available to you, please go to https://www.xfinity.com/learn/internet-service.

Comcast provisions its customers' modems and engineers its network with the goal of enabling customers to enjoy the speeds to which they subscribe. Comcast also provides minimum system recommendations for each of the speed tiers it offers, which can be found at https://www.xfinity.com/support/internet/requirements-to-run-xfinity-internet-service/. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of service to which a customer subscribes. As Comcast makes clear in its advertising and pricing information disclosures, "Actual speeds vary and are not guaranteed." The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of Comcast as an Internet Service Provider ("ISP").

THESE CONDITIONS INCLUDE:

1. Performance of a customer's computer, including factors such as its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections between the computer and the router or modem may be generally slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference, attenuation, and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to some of the same limitations mentioned above.
3. The distance and time it takes packets to travel between a customer's modem and their final destination on the Internet, or their point of origination and a customer's modem, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks, as well as the capacity of the facilities the edge provider (i.e., any provider of content, applications, or services over the Internet) has chosen to route its traffic to Comcast's network (and the interconnection capacity it has arranged), may affect the overall speed of an Internet connection.
4. Congestion or high usage levels at the edge provider or destination. When you access an edge provider or particular destination that is being visited by others at the same time, you may experience a slower connection if the edge provider or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the edge provider or destination. To control traffic or performance, many edge providers limit the speeds at which a visitor can download from their site. Those speed limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds, such as DOCSIS 2.0 devices or early DOCSIS 3.0 devices. Comcast has a Device-to-Product Enforcement ("DPE") program to identify when customers may be using incompatible or old modem devices, whether leased or owned, and provides instructions on how to obtain new modems capable of receiving the speeds and features included with their service. Additionally, Comcast encourages its customers to promptly contact customer service if they have any concerns about their modem performance or speed capabilities. Please visit MyDeviceInfo for information regarding cable modems approved for use on Comcast's network and to determine which devices can support various speeds.

Speed

The Federal Communications Commission ("FCC") conducts an ongoing, rigorous study of the performance of the largest ISPs in the United States ("Measuring Broadband America"), including Comcast. The most recent report from this study can be found on the FCC's website. The FCC determined that Comcast's Xfinity Internet services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, known as "peak" times, during sustained testing. Peak times are Monday through Friday from 7:00pm to 11:00pm local time.

Below are the median download and upload speeds by tier. Unless a speed tier is noted with an asterisk (*), the reported information comes from the latest FCC study. We are including the FCC's measurement of the 105 Mbps speed tier, which we no longer offer, on an interim basis until internal measurements of our 100 Mbps speed tier are completed, but we do not expect the results to differ significantly. Service tiers noted with an asterisk were not included in the FCC's study either because they are newer products with limited availability or they do not meet the study's reporting requirements. For these noted tiers, the information below is based on data compiled independently by Comcast using a largely similar testing methodology.

Download Speed Tier	Measured	Upload Speed Tier	Measured
5*	5.95 Mbps	1	1.21 Mbps
10*	11.8 Mbps	1	1.21 Mbps
10*	11.8 Mbps	2	2.4 Mbps
25	28.90 Mbps	0.768	0.89 Mbps
50	57.56 Mbps	5	5.91 Mbps
75	85.38 Mbps	10	11.87 Mbps
105	110.81 Mbps	5	5.91 Mbps
150	151.65 Mbps	20	(2)
200*	212.2	10	11.5
250*	265.1 Mbps	25	29.7 Mbps
300*	318.2 Mbps	25	29.7 Mbps
*Based on independent measurements by Comcast		(2)Not reported by Measuring Broadband America

Comcast's Xfinity Internet services also deliver over 100 percent of their advertised downstream and upstream speeds during periods of time when Internet usage is generally lighter, known as "off peak" times, during sustained testing. Below are the Comcast median speeds by tier during off peak times:

Download Speed Tier	Measured Speed	Upload Speed Tier	Measured Speed
5*	5.95 Mpbs	1	1.21 Mpbs
10*	11.8 Mpbs	1	1.21 Mpbs
10*	11.8 Mpbs	2	2.4 Mpbs
25	29.36 Mpbs	0.768	0.90 Mpbs
50	58.59 Mpbs	5	5.93 Mpbs
75	88.61 Mpbs	10	11.89 Mpbs
105	120.05 Mpbs	5	5.93 Mpbs
150	168.29 Mpbs	20	(2)
200*	224.3 Mpbs	10	11.7 Mpbs
250*	292.5 Mpbs	25	29.9 Mpbs
300*	336.5 Mpbs	25	29.9 Mpbs
*Based on independent measurements by Comcast		(2)Not reported by Measuring Broadband America

While individual experiences may vary, the FCC's tests have consistently confirmed the quality of Comcast's Xfinity Internet services.

You also can test your speeds yourself. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast's network from the customer's computer to test sites located throughout Comcast's network. Simply go to http://speedtest.xfinity.com to test your connection. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

There are other speed tests that measure Internet performance. We have provided links to a few of these sites below for your reference. Please note, however, that all speed tests have limitations and flaws. Each of these tests measures limited aspects of an ISP's speed and therefore must be seen as a guide rather than definitive measurements of performance.

• http://www.speedtest.net
• http://netalyzr.icsi.berkeley.edu

 

Latency

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience. Comcast has no basis for saying what level of latency should be expected by any particular user at any particular time but notes that the measured results from Measuring Broadband America as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

Measuring Broadband America measures latency using packet tests that calculate the time it takes for packets to travel from a customer location to a target test node and back. Below are the Comcast median latency results by tier during peak times (as defined above), during sustained testing:

Speed Tier	Latency
Down 5*	12.3 ms
Down 10*	16.4 ms
Down 25	20.90 ms
Down 50	25.20 ms
Down 75	18.74 ms
Down 105	23.98 ms
Down 150	19.20 ms
Down 200*	19.7 ms
Down 250*	24.3 ms
Down 300*	39.1 ms
*Based on independent measurements by Comcast

Below are the Comcast median latency results by tier during off peak times, during sustained testing:

Speed Tier	Latency
Down 5*	11.7 ms
Down 10*	13.7 ms
Down 25	19.83 ms
Down 50	24.96 ms
Down 75	18.46 ms
Down 105	23.67 ms
Down 150	18.75 ms
Down 200*	20.2 ms
Down 250*	23.2 ms
Down 300*	37.3 ms
*Based on independent measurements by Comcast

These results do not define latency as part of a particular user experience because:

1. The results include time spent traversing networks not controlled by Comcast;
2. The geographic distance between any given user and the target node may vary greatly from those employed in Measuring Broadband America.

Customers can test the latency characteristics of their service at Xfinity Speed Test. Of course, this test also may reflect limitations in a customer's home network (especially Wi-Fi) and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

There are other latency tests available on the Internet. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance.

Packet Loss

Packet loss is a third measurement of Internet performance. Packet loss is the percentage of packets that are sent by the source but not received by the destination. This is sometimes due to congestion along the route but may also reflect an impairment in a customer's home network, including their Wi-Fi and coaxial cable network as well as the connection from the customer's home to the Comcast network. Customers should diagnose their home network for possible repair if packet loss is high. Packet loss is also a normal part of the Transmission Control Protocol (TCP), and signals to a sender to slow their sending rate to adjust to available bandwidth along a network path. As a result, a small amount of packet loss is expected and normal, but it is unlikely to directly affect the perceived quality of applications that request retransmission of lost packets, such as web browsing and email. In addition, measures to further reduce packet loss would require unacceptable increases in latency. However, packet loss may affect the perceived quality of applications that do not request retransmission of lost packets, such as VoIP phone calls and video chat. Nevertheless, packet losses of a few tenths of a percent are sufficiently small so that they are unlikely to significantly affect the perceived quality of these applications. The Internet's technical community continues to debate the merit and meaning of packet loss measurement. Comcast has no basis for saying what level of packet loss should be expected by any particular user at any particular time but notes that the measured results from Measuring Broadband America as to past performance are perhaps the closest one can come to identifying expectations of future performance as well.

Measuring Broadband America includes packet loss tests performed using packet tests that measure the time it takes those packets to travel from a customer location to a target test node and back. Packets not received back within three seconds of sending were treated as lost. Below are the Comcast average packet loss results by tier during peak times (as defined above), during sustained testing. Comcast currently does not have packet loss data for our 5, 10, 200, 250, and 300 Mbps services tiers. However, based on the MBA data, we expect packet loss to be in the range of 0.08% to 0.10%.

Speed Tier	Packet Loss
Down 25	0.10%
Down 50	0.08%
Down 75	0.10%
Down 105	0.06%
Down 150	0.10%

Below are the Comcast average packet loss results by tier during off peak times, during sustained testing. Comcast currently does not have packet loss data for our 5, 10, 200, 250, and 300 Mbps services tiers. However, based on the MBA data, we expect packet loss to be in the range of 0.06% to 0.10%.

Speed Tier	Packet Loss
Down 25	0.06%
Down 50	0.10%
Down 75	0.07%
Down 105	0.07%
Down 150	0.07%

Customers can test their packet loss by performing ping tests or other tests. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance. These tests are heavily dependent on several of the factors outlined above, especially the customer's in-home Wi-Fi network. Therefore, these tests do not necessarily reflect the performance of the Comcast network alone.

Xfinity WiFi

In addition to the residential or commercial Internet service that you enjoy at your home or office, Comcast provides its Internet subscribers with Xfinity WiFi, which allows Xfinity Internet subscribers to access the Internet when they are at one of the many Xfinity or Cable WiFi hotspots. Comcast engineers the underlying network to deliver high-performance access to the Internet. However, the performance you experience, once you connect to the hotspot, may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your Wi-Fi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many of the factors already mentioned above. These Wi-Fi hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that our use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided solely on a "best efforts" basis.

PUBLISHED: JUNE 22, 2015

NetForecast completed a comprehensive study of Comcast's usage meter platform covering a 16-month period between January 2014 and April 2015. The report provides an overview of how our usage management platform works, methodology used to measure and validate accuracy, along with the overall performance rating. In short, NetForecast rates Comcast's usage meter accuracy as Excellent with an APDEX score of 0.94. The results of the study have been published on NetForecast's website.

PUBLISHED: NOVEMBER 6, 2014

The Internet Society (ISOC) has published Mutually Agreed Norms for Routing Security (MANRS), as a follow-up to their Routing Resilience Manifesto. Comcast joins ISOC and other network operators in calling for community action on this subject, and joining us to support this MANRS.

Primarily, adoption of the Mutually Agreed Norms for Routing Security requires that Internet Service Providers (ISPs) explicitly filter routing announcements received from their customer networks at the "prefix" level. Comcast has been employing this method for at least the past several years and expects neighboring networks to do the same.

Additionally, this calls for networks to take steps to prevent network spoofing, which is central to curtailing many amplification and/or distributed denial of service (DDoS) attacks. These attacks take advantage of the fact that some networks have not taken steps to prevent network address spoofing.

Comcast takes several steps to prevent network spoofing, and a list of FAQs on subject can be found here.

Finally, the Mutually Agreed Norms for Routing Security asks that ISPs maintain usable contact information and coordination capability for real-time troubleshooting between network operators, to which Comcast is also committed. We hope that other ISPs will adopt the guidance in the Mutually Agreed Norms for Routing Security in order that we may improve the stability and reliability of the Internet upon which we all depend.

PUBLISHED: OCTOBER 21, 2014

In response to malicious network activity, we have implemented a block of TCP port 0 traffic. The Internet Assigned Numbers Authority (IANA) lists TCP port 0 as a reserved port, which means it should not be used by applications. Based on testing, we believe this block prevents network abuse and should not impact legitimate traffic. A full list of blocked ports can be found here.

PUBLISHED: JULY 3, 2014

At Comcast, we periodically review and revise our website to ensure that customers have the latest information about our services. We have revised our Internet service performance webpage to give customers the latest information to help them make informed choices. You can read more about the performance of our Internet service here.

Your Internet Service Performance

Comcast provides residential and commercial customers with a variety of high-speed Internet plans from which to choose, with download speed tiers ranging from up to 3 megabits per second ("Mbps") to up to 250 Mbps (in select markets) and upload speeds ranging from up to 768 kilobits per second ("kbps") to up to 25 Mbps on our DOCSIS 3.0 cable network. In select markets we also offer a fiber-based service with download speeds up to 505 Mbps and upstream speeds up to 100 Mbps. To see the plans currently available to you, please go to http://www.comcast.com/internet-service

Comcast provisions its customers' modems and engineers its network to enable customers to enjoy the speeds to which they subscribe. However, Comcast does not guarantee that a customer will achieve those speeds at all times. Unless a customer purchases a dedicated Internet connection, no Internet Service Provider ("ISP") can guarantee a particular speed at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of service to which a customer subscribes. The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of an ISP. These conditions include:

1. Performance of a customer's computer, including its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections between the computer and the router or modem may be slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to some of the same limitations mentioned above.
3. The distance packets travel (round trip time of packets) between a customer's computer and their final destination on the Internet, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the capabilities of those networks may affect the overall speed of that Internet connection.
4. Congestion or high usage levels at the website or destination. When you access a site or particular destination that is being visited by others at the same time, you may experience a slower connection if the site or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the website or destination. To control traffic or performance, many websites limit the speeds at which a visitor can download from their site. Those limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds. Please visit MyDeviceInfo for information regarding cable modems approved for use on Comcast's network.

Speed

Recently, the Federal Communications Commission ("FCC") concluded a nationwide network performance test of the largest ISPs in the U.S., including Comcast. The results of that test can be found at http://www.fcc.gov/reports/measuring-broadband-america-2014. According to that test, Comcast's XFINITY Internet services deliver, on average, over 100 percent of their advertised downstream and upstream speeds during the busiest periods of the day, during sustained testing. Below are the Comcast results by tier:

Speed
Down (Mpbs)		Up (Mbps)
Tier	Measured	Tier	Measured
3	3.39	0.768	0.89
20	21.07	4	4.45
25	27.33	5	5.74
50	53.21	10	11.05

While individual experiences may vary, the FCC's tests have consistently confirmed the quality of Comcast's XFINITY Internet services.

You also can test your speeds yourself. Comcast offers its customers the ability to test the speeds that they are receiving on Comcast's network - from the customer's computer to test sites located throughout Comcast's network. Simply go to http://speedtest.xfinity.com to test your connection. These tests are heavily dependent on many of the factors outlined above, however, and therefore do not necessarily reflect the performance of the Comcast network alone.

There are other speed tests that measure Internet performance. We have provided links to a few of these sites below for your reference. Please note, however, that all speed tests have limitations and flaws. Each of these tests measures limited aspects of an ISP's speed and therefore must be seen as a guide rather than definitive measurements of performance.

• http://www.speedtest.net
• http://netalyzr.icsi.berkeley.edu
• http://www.broadband.gov/qualitytest/about/

 

Latency

Latency is another measurement of Internet performance. Latency is the time delay in transmitting or receiving packets on a network. Latency is primarily a function of the distance between two points of transmission, but also can be affected by the number and quality of the network or networks used in transmission. Latency is typically measured in milliseconds, and generally has no significant impact on typical everyday Internet usage. As latency varies based on any number of factors, most importantly the distance between a customer's computer and the ultimate Internet destination, it is not possible to provide customers with a single figure that will define latency as part of a user experience.

As discussed above, the FCC recently concluded a nationwide network performance test of the largest ISPs in the U.S., including Comcast. Latency tests were performed using User Datagram Protocol ("UDP") packet tests that measure the round trip time it took those packets to travel between a customer location and a target test node. According to the FCC's test results, the cable industry average latency was approximately 32 milliseconds, and DSL averaged 49 milliseconds. Below are the Comcast results by tier:

Speed Tier (Mbps)	Latency
Down 3, Up 0.768	38.99 ms
Down 20, Up 4	30.97 ms
Down 25, Up 5	38.99 ms
Down 50, Up 10	37.74 ms

The results do not define latency as part of a particular user experience because (1) the results include time spent traversing networks not controlled by Comcast; and (2) the geographic distance between any given user and the target node may vary greatly from those employed in the FCC's broadband measurement project. But customers can test the latency characteristics of their service at http://speedtest.xfinity.com. Of course, this test also may incorporate limitations in a customer's home network and computers, and therefore will not necessarily reflect the performance of the Comcast network alone.

There are other latency tests available on the Internet. We have provided links to a few of these sites, above in the Speed Test Section, for your reference. As previously explained, however, all tests have limitations and flaws, and therefore must be seen as a guide rather than definitive measurements of performance.

 

XFINITY WiFi

In addition to the residential or commercial Internet service that you enjoy at your home or office, Comcast provides its Internet subscribers with XFINITY WiFi, which allows XFINITY Internet subscribers to access the Internet when they are at one of the many XFINITY or Cable WiFi hotspots. Comcast engineers the underlying network to deliver high-performance access to the Internet. However, the performance you experience, once you connect to the hotspot, may vary based on any number of factors, such as the number of other subscribers trying to use the same hotspot at the same time, your computer or wireless device, your Wi-Fi receiving antenna, your distance from the hotspot router, attenuation from walls and foliage, and interference from other devices using the same spectrum, in addition to many of the factors already mentioned above. These WiFi hotspots use spectrum that the FCC has allocated for "unlicensed" use, which means that our use of this spectrum is not protected from interference from other devices using the same spectrum in the same geographical area. This makes it inherently difficult to predict the kind of performance you can expect. Therefore, this service is provided on a "best efforts" basis.

PUBLISHED: JULY 2, 2014

The Internet Society (ISOC) published a so-called Routing Resilience Manifesto. Comcast joins ISOC and other network operators in calling for community action on this subject, and joining us to support this Manifesto.

Primarily, adoption of the Routing Resilience Manifesto requires that Internet Service Providers (ISPs) filter routing announcements received from their customer networks explicitly at the prefix level. Comcast has been employing this method for at least the past several years and expects neighboring networks to do the same.

Additionally, the Routing Resilience Manifesto calls for networks to take steps to prevent network spoofing, which is central to curtailing many amplification and/or distributed denial of service (DDoS) attacks. These attacks take advantage of the fact that some networks have not taken steps to prevent network address spoofing. Comcast takes several steps to prevent network spoofing, and a list of FAQs on subject can be found here.

Finally, the Manifesto asks that ISPs maintain usable contact information and coordination capability for real-time troubleshooting between network operators, to which Comcast is also committed. We hope that other ISPs will adopt the guidance in the Routing Resilience Manifesto in order that we may improve the stability and reliability of the Internet upon which we all depend.

PUBLISHED: MAY 28, 2014

NetForecast's independent assessment of Comcast's data usage meter confirms it to be accurate within +/-1% with an APDEX score of .98, which is described as excellent. The report provides an overview of how our usage management platform works, NetForecast's validation methodology, and the overall performance rating. We recently contracted with them to conduct the comprehensive study, and the results have been published on their website.

PUBLISHED: MARCH 28, 2014

On May 20, 2011, we first posted about these rules. Those rules have now been updated to reflect that IPv6 is now required, that DOCSIS 1.1 and 2.0 modems are now or soon will be in end-of-life status, and that we are preparing for DOCSIS 3.1 modems.

These rules pertain to the attachment of devices to our High-Speed Internet network by customers. You can find information concerning the devices approved for use on the network, and the tiers of our service that they are appropriate for at My Device Info. In order for a cable modem device to be approved for use on the network, it must pass CableLabs certification, UL certification, FCC certification, and Comcast DOCSIS certification testing. Comcast's current DOCSIS device testing requirements and the test scheduling process are described here.

Please also note that customers may purchase their own cable modem for use on the Comcast network. However, Comcast does not support all possible modems on its network because there may be compatibility issues with some devices. The Comcast Agreement for Residential Services (Sections 6(b)(1)-(3)) makes clear that a device must meet Comcast's minimum technical specifications in order to successfully install, access, operate or use a particular service. In addition to our full list of approved devices, a list of recommended retail devices can be found at My New Modem.

PUBLISHED: MARCH 13, 2014

Recently, the Internet community has taken notice of NTP amplification attacks, as well as other attacks leveraging DNS, SNMP, and other protocols. These attacks take advantage of the fact that some networks have not taken steps to prevent network address spoofing. Since we have been asked what steps Comcast takes to prevent network spoofing, we have put together an FAQ on the subject.

Background

In short, we use one of two techniques: Unicast Reverse Path Forwarding (uRPF) verification and DOCSIS Source Address Verification (SAV). Using these techniques our customers are prevented from sending traffic with spoofed IP addresses through their cable modems.

Computers and other devices connected to the Internet use IP (Internet Protocol) addresses to establish end-to-end communications. Most devices use a single IP address, though some have several. Successful communication relies on both the source and destination addresses being encoded in packets sent between the systems to enable two-way interactions. Thus, your packet has the destination address, as well as the return (source) address, much like a letter.

Problems

Many network attacks make use of the ability to "spoof" or "forge" the source IP address in a packet. By using this forged source address, it can make it difficult or impossible to trace the source of an attack. In addition, this can be used to take down networks in large-scale Distributed Denial of Service (DDoS) attacks where many computers are told to send a response to the forged source address.

Unfortunately, the Internet's architecture does not prohibit source address spoofing by default; network operators are relied upon to do so.

Solutions

Since each device on the Internet should be assigned a given IP address, rules and configuration settings on the source network must be used to ensure that that device cannot send packets with a source address that was not assigned to it. Proper configuration and policy that effectively block IP spoofing go a long way to cutting down on the avenues available for abuse and attack on the network. This recommendation has been enshrined by the Internet engineering community as Best Current Practice #38, or BCP38 for short, and published by the IETF (Internet Engineering Task Force) in its Request For Comments (RFC) document series as RFC2827.

Comcast's Efforts to Prevent IP Address Spoofing

Comcast implements "source address filtering" or "source address validation" as a basic technique to prevent IP address filtering. As a result, we implement BCP38/RFC2827 in our network.

To do this in our subscriber network we use one of two techniques: a technique known as Unicast Reverse Path Forwarding (uRPF) verification, and implementation of DOCSIS Source Address Verification (SAV). Using these techniques our customers are prevented from sending traffic with spoofed IP addresses through their cable modems. uRPF is described in RFC3704 and SAV is described in Section 9.6 of the DOCSIS 3.0 standard's security specifications. Using these methods, customers are prevented from sending traffic with spoofed IP addresses through their cable modems.

Although Comcast does its best to prevent IP address spoofing, there are situations where applying uRPF checking is not feasible or practical. This includes services for some commercial customers that have multiple Internet service providers, known as multi-homing. In cases such as these, Comcast can and does provide guidance to such customers so that they can effectively implement uRPF or similar checking within their own networks. BCP84/RFC3704, elaborates further on these cases.

The Internet Community

Implementation of techniques to prevent IP address spoofing can be thought of as an "environmental benefit" for the Internet.

When implemented by Comcast or another network operator, these measures don't only or even primarily benefit that operator's customers. Rather, they benefit the broader community by plugging security holes in the Internet, and preventing more widespread DDoS attacks that leverage spoofing. The broader the uptake of these techniques, the greater the improvement overall and the safer we all become on the Internet.

The FCC Communications Security, Reliability, and Interoperability working group is also working to improve this in the U.S. The FCC's CSRIC has studied this issue in the past and continues to do so.

Since Comcast prevents IP address spoofing and supports BCP38, what benefits does this have for the rest of the Internet?

Our techniques help limit malicious traffic that could otherwise come from Xfinity Internet customers, destined to or targeted at other Internet networks or servers. As a result, any attack launched from a Comcast subscriber will have the true IP address of the subscriber's cable modem and as such can be rapidly traced back and mitigated. As such it is not possible to use a Comcast residential Internet customer as an originating source for distributed denial of service (DDoS) attacks that use IP address spoofing to conceal the addresses of computers used in those attacks, such as a recent DNS amplification attack against an anti-spam organization or a recent NTP amplification attack against a content delivery network (CDN).

PUBLISHED: AUGUST 1, 2012

We've announced some changes our policies on Simple Network Management Protocol (SNMP) and Simple Mail Transport Protocol (SMTP), which will affect a very small portion of our customers. You can find more information in two blog posts. One is a general post about both issues, and the other is specific to SMTP. While the policy change was announced today, implementation will occur gradually.

PUBLISHED: MAY 17, 2012

We've announced some important changes - there's more information on our blog and our FAQs for more information. We will be revising our Acceptable Use Policies in the near future.

PUBLISHED: JANUARY 10, 2012

As noted here on our blog, we have signed all of our domain names and all customers are now using DNSSEC-validating resolvers. Comcast is the first large ISP in the North America to have fully implemented DNSSEC, as part of ongoing efforts to protect our customers with Constant Guard™ from Xfinity. In addition, Comcast Domain Helper has been turned off, as we noted here.

PUBLISHED: NOVEMBER 18, 2011

At Comcast, we periodically review and revise our website to ensure that customers have the latest information about our services. We have revised our Internet service performance and Internet 2go service performance webpages to give customers the latest information on these services and help them make informed choices.

Your Internet Service Performance

Comcast provides residential and commercial customers with a variety of high-speed Internet plans from which to choose, ranging from our Economy tier (with download speeds up to 1.5 megabits per second ("Mbps"), and upload speeds up to 384 kilobits per second ("kbps") to our Extreme 105 tier (with download speeds up to 105 Mbps, and upload speeds to 10 Mbps). Comcast provisions its customers' modems and engineers its network to enable its customers can enjoy the speeds to which they subscribe. However, Comcast does not guarantee that a customer will actually achieve those speeds at all times. Unless a customer purchases an expensive, dedicated Internet connection, no Internet Service Provider ("ISP") can guarantee a particular speed at all times. Comcast advertises its speeds as "up to" a specific level based on the tier of service to which a customer subscribes.

The "actual" speed that a customer will experience while using the service depends upon a variety of conditions, many of which are beyond the control of an ISP such as Comcast. These conditions include:

1. Performance of a customer's computer, including its age, processing capability, operating system, the number of applications running simultaneously, and the presence of any adware and viruses.
2. Type of connection between a customer's computer and modem. For example, in-home wireless connections between the computer and the router or modem may be slower than wired connections. In-home wireless connections also may be subject to greater performance fluctuations, caused by factors like interference and congestion. Comcast recommends that customers confirm that their in-home wireless connections are able to support the speeds that Comcast's services deliver. Certain older in-home wireless connections and routers cannot perform at the speeds delivered by Comcast's higher speed tiers. Customers can purchase their modem and router at a retail outlet, or they can lease the necessary equipment from Comcast, though even wireless routers leased from Comcast are subject to the same limitations mentioned above.
3. The distance packets travel (round trip time of packets) between a customer's computer and their final destination on the Internet, including the number and quality of the networks of various operators in the transmission path. The Internet is a "network of networks." A customer's Internet traffic may traverse the networks of multiple providers before reaching its destination, and the limitations of those networks will most likely affect the overall speed of that Internet connection.
4. Congestion or high usage levels at the website or destination. When you access a site or particular destination that is being visited by others at the same time, you may experience a slower connection if the site or destination does not have sufficient capacity to serve all of the visitors efficiently at the same time.
5. Gating of speeds or access by the website or destination. To control traffic or performance, many websites limit the speeds at which a visitor can download from their site. Those limitations will carry through to a customer's connection.
6. The performance of the cable modem you have installed. Modem performance may degrade over time, and certain modems are not capable of handling higher speeds. Please visit MyDeviceInfo for information regarding cable modems approved for use on Comcast's network.

Speed

Recently, the Federal Communications Commission ("FCC") concluded a nationwide network performance test of the largest ISPs in the U.S., including Comcast. The results of that test can be found at http://transition.fcc.gov/cgb/measuringbroadbandreport/Measuring_U.S._-_Main_Report_Full.pdf. According to that test, Comcast's Xfinity Internet services were shown to deliver, on average, over 100 percent of their advertised downstream and/or upstream speeds during the busiest periods of the day, during sustained testing. Below are the Comcast results by tier:

Comcast Tier Name	Speed
	Down (Mpbs)		Up (Mbps)
	Tier	Measured	Tier	Measured
Economy	1.5	1.46	0.384	0.42
Performance	12	12.44	2	2.24
Blast!	16	15.26	2	2.24
Blast!	20	20.41	4	4.61
Ultra	22	23.23	5	5.48

Again, while individual experiences may vary, the FCC's test validates the superior quality of Comcast's Xfinity Internet services.

Additionally, the FCC's speed tests did not include Comcast's new Performance Starter Tier or either of Comcast's Extreme Tiers: Extreme 50 or Extreme 105. Data gathered from our own speed tests show that the average speed customers experience should fall at or near the advertised downstream and upstream speeds. The results of our testing are as follows:

Comcast Tier Name	Speed
	Down (Mpbs)		Up (Mbps)