Comcast Network Management

Your Broadband Internet Access Service Performance

Published: April 21, 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.

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.

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