Reflections on Comcast-BitTorrent
The collaboration between Internet service provider (ISP) giant (and cable MSO) Comcast and BitTorrent, the company associated with the peer-to-peer (P2P) protocol of the same name, points to a protocol-agnostic future way of managing high-speed data networks.
It also echoes news that surfaced two weeks ago at the Distributed Computing Industry Association’s (DCIA) P2P Market Conference in New York regarding Verizon’s testing of a managed P2P initiative known as P4P.
Those test results indicated that by making known the location of users, Verizon could reduce the average number of hops involved in a file sharing sequence from more than five to less than one – or from 5.5 to 0.89, as ZDNet‘s Richard Konan reported on March 14.
There was no mention of P4P in the Comcast release. (For more on P4P, see the relevant downloads at the DCIA Web site).
What Comcast CTO Tony Werner did state was that Comcast had held "several months" of talks with "leaders in the Internet community," resulting in the MSO’s decision to migrate by the end of 2008 to a "capacity management technique that is protocol agnostic."
As a leader in that community, BitTorrent CTO Eric Klinker offered this concession: "We understand why Comcast and other ISPs adopted the approach that they did initially."
Both companies agreed to include other ISPs, technology companies and the Internet Engineering Task Force (IETF) in their collaboration, the goal being "a new distribution architecture for the efficient delivery of rich media content." Truce in the battle That BitTorrent, and P2P apps in general, have upset the cable industry’s high-speed data service model is no secret. One story from two years ago involving a small Canadian operator’s adoption of a technique called unsolicited grant service (UGS) to nail down voice service is worth recalling, anecdotal as it may be.
"In the early days, we found that even though we used all the normal quality of service (QoS) settings, it really didn’t work," said Bruce Marshall, technical director of Hamilton, Ontario-based Mountain Cablevision. "Particularly, BitTorrent just clobbered the telephone traffic." For more, click here.
Those on the P2P side of the aisle, however, have seen things somewhat differently. In particular, they have taken a dim – if not combative – view of the Comcast’s approach to high-speed data network management.
In a story filed February 19 on The Register, a P2P user group site, Cade Metz reported that three staffers at BitTorrent had proposed "a new extension to the popular P2P protocol that would circumvent Comcast’s self-described ‘reasonable network management.’"
How that proposal (threat?) may have played into the Comcast/BitTorrent discussions (negotiations?) is a matter for speculation. But it is worth mentioning that some consumers, most recently in a class action suit filed in the Superior Court for the District of Columbia discussed here, have quite openly and separately entered the fray.
In any case, the upshot of Comcast’s discussions with BitTorrent, a comparatively minuscule software shop, is striking. "We will have to rapidly reconfigure our network management systems," stated Werner in today’s release.
In concrete terms, that suggests a move away from deep packet sniffing as championed by vendors such as Sandvine and a move toward techniques that can monitor congestion, especially on the south-bound or HFC access side of the cable data network. Whether Comcast home-grows that technology or leans upon something like ARRIS’s Fair Bandwidth Manager application or actually implements something in collaboration with BitTorrent et al. remains to be seen.
– Jonathan Tombes
