Comcast Spells Out How It Will Curb Internet Hogs

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Comcast will use equipment from Sandvine, Camiant and a third yet-to-be-determined vendor to temporarily throttle back the speeds of the heaviest Internet users during times of network congestion, the operator disclosed in regulatory filings.

Comcast outlined the plans to migrate to a “protocol-agnostic” bandwidth management technique by the end of 2008 in documents filed Friday with the Federal Communications Commission. The company was responding to an FCC order that it stop specifically targeting peer-to-peer applications, and adopt a more neutral technique.

“The goal of Comcast’s new congestion management practices will be to enable all users of our network resources to access a ‘fair share’ of that bandwidth, in the interest of ensuring a high-quality online experience for all of Comcast’s [high-speed Internet] customers,” the operator said in the FCC filings.

Sandvine, in a statement Monday, said terms of the agreement have not yet been finalized. Based in Waterloo, Canada, Sandvine demonstrated the Fairshare system at The Cable Show ’08 in May.

Comcast acknowledged that it currently uses Sandvine’s Policy Traffic Switch 8210 to limit the number of upstream connections certain P2P applications can initiate. Under the new technique, Comcast will use the vendor’s Fairshare tool to determine when a cable modem termination system (CMTS) port is close to being congested.

In addition, the MSO said it will use Camiant’s PacketCable Multimedia servers to instruct a cable modem termination system (CMTS) which specific modem should be curtailed. A third component, an Internet protocol detail record (IPDR) server, will analyze cable modem volume usage, but Comcast said it has not yet selected a vendor.

Comcast expects to cut over to commercial deployment of the protocol-agnostic systems starting Nov. 15, with its entire footprint converted by Dec. 31, according to its FCC filings.

The system will deprioritize bandwidth for “high-consumption” subscribers, which Comcast defined as one who has used an average of 70% or more of his or her provisioned upstream or downstream bandwidth over a particular 15-minute period during periods of network congestion. A user is removed from the penalty box once his or her usage falls below 50% of provisioned bandwidth for 15 minutes.

Comcast currently operates about 3,300 CMTSs, serving 14.4 million high-speed Internet customers. On average, the company said in the FCC filings, about 275 cable modems share the same downstream port and about 100 share the same upstream port.

The cable company has conducted trials of protocol-agnostic management platforms over the past few months in Chambersburg, Pa.; Warrenton, Va.; Lake City and East Orange, Fla.; and Colorado Springs, Colo.

Based on those trials, Comcast said, fewer than one-third of 1% of subscribers have had their traffic priority status flagged for excessive consumption. For example, in Colorado Springs last month, an average of 22 users out of 6,016 total in the trial market were affected at some point during the day.

Comcast told the FCC is has yet to receive “a single customer complaint in any of the trial markets that can be traced to the new congestion management practices, despite having broadly publicized its trials.”

In March, Comcast had said it would move to a “protocol-agnostic” approach by year-end. That was prior to the FCC issuing its official order last month.

In addition to BitTorrent, Comcast said in its filings that it has used Sandvine’s PTS 8210 to target four other peer-to-peer applications that consume an extraordinary amount of bandwidth: Ares, eDonkey, FastTrack and Gnutella.

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