Comcast is upgrading its residential cable internet service to offer upload and download speeds of up to 2 Gbps through decades-old coaxial cables. The company says it’s the first ISP in the world to offer multi-gigabit symmetrical speeds to customers through DOCSIS 4.0 technology, which it’s powering through the Xfinity 10G network.

The zippy X-Class Internet service will first be available in some neighborhoods in Colorado Springs, Colorado starting next week. It will arrive in parts of Atlanta and Philadelphia soon, and then in other markets over the next few years.

Comcast says DOCSIS 4.0 connections are already available in tens of millions of homes across the US. Multi-gigabit download speeds have been possible via cable for several years. Upgrading to DOCSIS 4.0 will not only improve download speeds but make it possible to deliver symmetric uploads while minimizing lag and avoiding any impact to downstream service.

Comcast has been working on this technology for several years and it aims to offer 2 Gbps symmetrical service in more than 50 million homes by the end of 2025. Since they’ll be able to access faster connections through existing coaxial cable infrastructure, many consumers won’t need to wait for Comcast to connect their home to a fiber network before they can make the most of multi-gigabit upload and download speeds.

What’s more, DOCSIS 4.0 is capable of supporting up to 10 Gbps downstream and up to 6 Gbps upstream speeds, so coaxial cables may be able to carry even faster internet connections in the future. In a test last year, Comcast achieved download speeds of 6 Gbps and upload speeds of 4 Gbps.