Comcast Network Management

Comcast is committed to providing the best online experience possible for all of its customers. The company uses reasonable network management practices that are consistent with industry standards.

Managing the network is essential as Comcast works to promote the use and enjoyment of the Internet by all its customers.


More questions? View our Network Management FAQs

Recent Network Management News:

DNSSEC Deployment Completed, Domain Helper Deactivated
Tuesday, 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.

Your Internet Service Performance
Friday, 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. You can read more about the performance of these services here and here.

IPv6 Pilot Market Deployment Begins
Wednesday, November 9, 2011

Comcast has started our first pilot market deployment of IPv6. This first phase supports directly connected CPE, where a single computer is directly connected to a cable device. A subsequent phase will support home gateway devices. To learn more, check out FAQs on the pilot market deployment and the announcement and technical details on our blog.

Rules Regarding the Attachment of Devices to the Network
Friday, May 20, 2011

Does Comcast have rules regarding the attachment of devices to our High-Speed Internet network by customers? Yes, and 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 http://mydeviceinfo.comcast.net. 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.

Your Internet Service Speeds
Thursday, March 10, 2011

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 ensure that 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. Without purchasing an expensive, dedicated Internet connection, no Internet service provider (“ISP”) can guarantee a particular speed at all times to a customer. Comcast advertises its speeds as “up to” a specific level based on the tier of service to which a customer subscribes. Read much more about this topic here.

Updated Network Management FAQs
Friday, January 28, 2011

Comcast created this site in 2008 to transparently disclose our network management practices, and we have updated it with relevant information since its inception. Today, we have updated our network management FAQs to describe and explain our current network management practices for our high-speed Internet services.

DNSSEC Rollout Begins
Monday, October 18, 2010

As noted on our blog, starting today we will begin migrating customers who have opted out of our Domain Helper service over to our production DNSSEC-validating servers. This will happen first in a selected part of our Virginia network, and will later expand to all markets in the following sixty days, at which point all of our customers who have opted out of Domain Helper will be migrated. After this has been completed, we will migrate the rest of our customers, which we anticipate will stretch into the early part of 2011. To understand what will happen when a DNSSEC validation failure occurs, see this validation failure FAQ. You may also want to check out this brief introductory video about DNSSEC, as well as our Constant Guard™ page. We've also updated all of our DNSSEC FAQs here.

Constant Guard™ Bot Detection and Notification National Rollout Begins
Thursday, September 30, 2010

In October 2009, we announced the market trial of our new Constant Guard™ bot detection and notification system. The system was designed to detect bot activity and send customers a "Service Notice" when we believe their computer has been infected with a bot or other malware. Based on the success of the market trial, we have decided to rollout the bot detection and notification system to our entire network over the next few months. For additional information, feel free to visit our blog post or our Constant Guard™ page.

DNSSEC Update - .ORG TLD Signed, All Comcast .ORG Domains Signed
Wednesday, June 23, 2010

Today in Brussels, the Public Interest Registry, operator of the .ORG Top Level Domain (TLD), announced that they have signed the .ORG TLD, enabling support for DNSSEC in that TLD. Coinciding with that announcement and joint testing we have performed with PIR, Comcast is pleased to sign all of our over 650 .ORG domains. This is an important milestone in our continuing work to deploy DNSSEC. You can learn more about this on the Comcast DNSSEC Information Center website at http://www.dnssec.comcast.net and you can find slides we will be presenting at two ICANN DNSSEC workshops tomorrow here andhere.

Broadband Internet Technical Advisory Group Announced
Wednesday, June 9, 2010

Comcast, along with other leading high-tech companies, announced the formation of the Broadband Internet Technical Advisory Group, or 'BITAG' for short. The BITAG will focus on network management issues, among other topics. For more information, please see a post on our blog here.

DNSSEC Implementation Plans Announced
Tuesday, February 23, 2010

Comcast has been a leader in testing of and advocating for the wide adoption of DNSSEC. Our leadership continues today with the announcement of a plan to implement DNSSEC validation in the DNS servers that our customers use by the end of 2011, as well as for signing of our authoritative domains, such as comcast.com, by the end of the first quarter of 2011. In addition, today we are making available DNSSEC-validating DNS servers for customers to use on a trial basis now. You can learn more about this on the Comcast DNSSEC Information Center website at http://www.dnssec.comcast.net.

IPv6 Technical Trials for 2010 Announced
Wednesday, January 27, 2010

Comcast has been a leader in IPv6 development for many years. Our leadership continues today with the announcement of a plan to conduct real, production-network trials of IPv6 technology this year. The transition from IPv4 addresses to IPv6 addresses is a necessity, as the available pool of IPv4 addresses will at some point be exhausted for all Internet users.

These trials will help Comcast to identify and solve any areas of difficulty involved in the transition to IPv6, and to determine what approach will be the easiest and most seamless to our customers. Comcast will continue to share what we learn with the Internet community, particularly with the IETF, for the benefit of other users of the Internet.

Customers who are interested in volunteering to participate in these IPv6 trials, can express their interest using the online form on the Comcast IPv6 Information Center website, at http://www.comcast6.net.

Data Usage Meter Pilot Market Deployment
Tuesday, December 1, 2009

Today we announced the start of a pilot market deployment of our data usage meter for our High-Speed Internet Service. This deployment begins today for customers in Portland, Oregon. We currently anticipate deploying this usage meter beyond the pilot market beginning in the first quarter of 2010. You can find FAQs here, and an independent analysis of the usage meter by NetForecast, Inc. here. The usage meter looks like this. Feel free to visit our customer support forums if you'd like to ask us more questions.

Comcast Participates in MIT Internet Traffic Analysis Study
Tuesday, October 20, 2009

The MIT Internet Traffic Analysis Study (MITAS) is a new research project at the MIT Computer Science and Artificial Intelligence laboratory (CSAIL). The goal of this project is to undertake novel empirical research of ISP traffic data. Data will be collected from at least six participating ISPs, including Comcast, and the project hopes to add more ISPs. Better data and collection methodologies are needed to inform the industry, the network research community, and policy discussions about appropriate technical and business approaches to traffic management.

Detailed traffic data will be collected from ISPs over time, enabling researchers to formulate empirically valid characterizations of both aggregate traffic patterns, as well as a traffic profile for the average users. It is important to note that no personally identifiable information about any participating ISPs' users will be used in this project.

More information about the MITAS research project can be found at the MITAS website, at http://mitas.csail.mit.edu.

Service Notice Trial Begins
Thursday, October 8, 2009

Today we announced our new Constant GuardTM security program. We are also testing a feature of Constant GuardTM called a "Service Notice," designed to send customers a message when we believe their computer has been infected with a virus or other malware. For additional information, please visit our blog post on this subject.

Prior to the start of this trial, we developed the a draft document with the Internet Engineering Task Force (IETF) regarding remediation of malicious bots, available for review and comment by the Internet community at http://tools.ietf.org/html/draft-oreirdan-mody-bot-remediation. In addition, for the same purposes, we have developed a draft document with the IETF which describes in detail how the Service Notice system works, available at https://datatracker.ietf.org/doc/draft-livingood-web-notification/.

Domain Helper National Rollout Begins
Tuesday, August 4, 2009

In July 2009, we announced our market trial of our new Domain Helper service, designed to help customers find Web sites they want when they mistype an address in the web browser's address bar. Based on the success of the market trial, we have decided to roll out the service to our entire network. Customers will receive an email explaining the service and how to opt-out shortly, but can certainly opt-out now as well. Please note that customers with statically-configured Comcast DNS servers are opted-out by default.

For additional information, feel free to visit our original blog post or our most recent blog post this subject. To find out how Domain Helper works, please click here.

Domain Helper Market Tests Begin
Thursday, July 9, 2009

At Comcast, we are constantly looking to deliver a better high-speed Internet and online search experience. That is why we have begun market testing Domain Helper in selected areas to help customers find the Web sites they want when they mistype a Web address name in a Web browser?s address bar. Those market areas are: Arizona, Colorado, New Mexico, Oregon, Texas, Utah, and Washington.

Some customers will not want the assistance of Domain Helper, so there is an easy way to opt-out of this when you receive the suggestion Web page (or by visiting the opt-out page now -- note also that customers with statically-configured Comcast DNS servers are opted-out by default). We have also developed the first draft of a new best practices document with the IETF regarding these types of services, available for Internet community review and comment at http://tools.ietf.org/html/draft-livingood-dns-redirect-00.

We hope our customers find this to be a valuable tool. For additional information, feel free to visit our blog post on this subject.

Network Management Update
Monday, January 5, 2009

In March 2008, we announced that by the end of the year Comcast would switch to a new network management technique for managing congestion on Comcast's broadband network. Effective December 31, 2008, we have completed this transition, which is now part of our daily business operations for managing congestion on our network. The approach is designed to ensure, to the greatest extent possible, that all of our high-speed Internet customers have fair and equal access to the Internet and to bandwidth resources.

On these Web pages, we have provided information and FAQs about congestion management and we have posted copies of the documents we filed with the FCC that also describe it in great detail. Please read more about network management or read some FAQs.

View full article.

Additional FAQs Posted on Security-Related Port Blocks
Tuesday, November 11, 2008

As part of continuing efforts to increase our transparency on our network management methods, we have updated and expanded our FAQs. We have recently published a new FAQ regarding the network ports which are blocked for security reasons, in order to protect our customers. It is available at here in our FAQs.

Network Management Update
Friday, November 7, 2008

Comcast is pleased to announce that we have successfully completed the trial of our new network management technique. We are now following through on our commitment to implement this new technique for managing network congestion across all areas of the country by the end of this year.

We will gradually transition to the new technique over the next few months and will conclude no later than December 31, 2008. The new technique is currently being used in the following areas: Minnesota, Indianapolis and Muncie, IN, Paducah, KY. Please click here to check for updates on the status of the transition to the new technique.

More questions? View our Network Management FAQs

IETF 73
Tuesday, November 4, 2008

IETF 73 will include P2P and network management-related topics, as a follow-up to the 72nd IETF meeting in July, 2008. The 73rd IETF meeting will take place in Minneapolis in November. We anticipate participating in a variety of working groups relevant to this topic, including Techniques for Advanced Networking Applications(TANA) and Application-Layer Traffic Optimization (ALTO) Birds of a Feather (BoF) meetings. In preparation for the ALTO BoF, where P4P-like mechanisms are being discussed, we have submitted in Internet Draft describing our recent P4P technical trial results, which is available here.

Network Management Update
Friday, September 19, 2008

Today, Comcast provided additional information to the FCC about how we manage congestion on our network, including detailed information about the future congestion management techniques we announced in March. More information and copies of these filings are posted here.

View full article.

Network Management Trial Expansion
Thursday, July 31, 2008

We are expanding our previously announced network management trial to the areas of Colorado Springs, CO, East Orange, FL, and Lake City, FL. We expect to continue these trials for at least 30 days as we evolve the new protocol-agnostic network management technique.

These trials which started in March 2008 are ongoing in the previously-announced markets of Warrenton, VA, and Chambersburg, PA

View full article.

IETF 72
Monday, July 21, 2008

IETF 72 will include P2P and network management-related topics, as a follow-up to the IETF P2PI Workshop in May. The 72nd IETF meeting will take place next week in Dublin, Ireland. While some of this follow-up work will occur in regular IETF workgroup groups, most of it will take place in the Techniques for Advanced Networking Applications (TANA) and Application-Layer Traffic Optimization (ALTO) Birds of a Feather (BoF) meetings. Comcast is participating in IETF 72.

Network Management Trial Update
Monday, June 2, 2008

The company announced in March 2008 that it will switch to a new network management technique by the end of the year for managing bandwidth use and congestion. The new network management technique is designed to ensure, to the greatest extent possible, that all Comcast High-Speed Internet customers have fair and equal access to the Internet and to bandwidth resources.

View full article on the trial, or see details of how the technique works.