Comcast launches ultra-low latency internet across major US cities
New technology promises sub-eye blink latency for gaming and video calls, expanding to multiple locations in 2025.
Comcast Corporation initiated deployment of ultra-low latency internet technology across major US cities on January 29, 2025, marking a significant technical advancement in consumer connectivity. The technology, which emerged from initial field trials in June 2023, reduces network response times to faster than an eye blink.
The implementation commenced in Atlanta, Chicago, Colorado Springs, Philadelphia, Rockville (Maryland), and San Francisco, according to Comcast's announcement. According to Emily Waldorf, Senior Vice President of Consumer Products at Comcast Connectivity and Platforms, the technology addresses evolving consumer demands beyond traditional speed metrics.
The technology, known as Low Latency DOCSIS (LLD), implements the Internet Engineering Task Force's (IETF) Low Latency Low Loss Scalable Throughput (L4S) open standards. These specifications enable network links to process latency-sensitive data packets differently, maintaining quality without impacting regular traffic flows.
Technical implementation details reveal that application developers must specifically mark their traffic as latency-sensitive using documented technical guidelines outlined in RFC 9330, 9331, and 9332. This marking process remains voluntary and requires no proprietary APIs or additional costs for developers.
Initial compatibility extends to several major platforms. Apple has integrated support across its ecosystem, including iPhone, iPad, Mac, Apple TV, and Apple Vision Pro devices running iOS 17, iPadOS 17, macOS Sonoma, and tvOS 17. Meta's mixed reality headsets, NVIDIA's GeForce NOW cloud gaming service, and numerous games on Valve's Steam platform have also implemented the technology.
The development process included extensive testing throughout 2024. Comcast conducted user group trials that demonstrated performance meeting or exceeding initial expectations. The technology operates through Comcast's existing network infrastructure, which currently serves more than 63 million homes and businesses across the United States.
For technical implementation, developers can access integration testing and certification services through Kyrio. The process requires adherence to specific technical guidelines, ensuring standardized implementation across different applications and services.
Early field trials, which began on June 16, 2023, utilized specific hardware configurations. Compatible equipment included the latest Xfinity 10G Gateway models (XB7 and XB8) and certain third-party devices such as the Arris S33 and Netgear CM1000v2 gateway.
Comcast's network architecture manages low latency application flows while maintaining bandwidth allocation and best-efforts prioritization for regular traffic. This technical approach ensures that non-marked traffic experiences no adverse effects on quality, speed, or latency.
The technology demonstrates particular benefits for applications requiring real-time interaction. Video conferencing platforms show improved quality and responsiveness, while gaming services benefit from reduced input lag. Virtual reality applications, which demand minimal latency for optimal user experience, also show enhanced performance.
Financial markets responded to the announcement with measured interest. Comcast's stock (CMCSA) traded at $37.30 on January 29, 2025, with a trading volume of 14,363,870 shares, according to market data from Refinitiv.
Industry implications suggest potential widespread adoption of the technology. The open standard nature of the implementation allows any content or application provider to integrate the technology into their products, potentially establishing a new baseline for consumer internet performance expectations.
The deployment represents a significant milestone in internet infrastructure development, building upon Comcast's previous network investments. The company has allocated substantial resources over the past decade to enhance and expand its network capabilities, though specific investment figures remain undisclosed in the announcement.