ISPs experimenting with new P2P controls

Peer-to-peer traffic management was a hot topic at this year's NXTcomm convention in Las Vegas, as keynote speakers and telecom industry panelists highlighted new methods for handling P2P traffic crunches.

ISPs' methods for managing P2P traffic have come under intense scrutiny in recent months after the Associated Press reported last year that Comcast was actively interfering with P2P users' ability to upload files by sending TCP RST packets that informed them that their connection would have to be reset. Because the RST packets did not appear to be sent directly from the company, critics accused Comcast of deceiving its customers and actively blocking their ability to share files online. Although Comcast has said it doesn't actively block any P2P protocols and merely "delays" P2P uploads during times of heavy congestion, the company has agreed to change its P2P traffic management policies and stop targeting traffic such as that of BitTorrent.

NXTcomm panelists and keynote speakers agreed that heavy P2P traffic could cause network management problems for ISPs. Typically, P2P technology such as BitTorrent distributes large data files by breaking them up into small pieces and sending them through multiple sources. After all the data is received, the file is then reassembled as a whole. But while this method of file sharing is much faster and more efficient than relying upon one centralized server, it also can cause significant network strain because P2P protocols are mainly designed to download large chunks of data from sources wherever they can be found, and without particular regard to network efficiency.

But despite their concerns about P2P's impact on the network, none of the speakers at NXTcomm endorsed the method of sending RST packets to all P2P users during peak hours. Rather, some said it was time to follow the lead of Comcast and begin implementing caps for individual users who are consuming disproportionately high amounts of bandwidth. This way, ISPs wouldn't be targeting individual P2P protocols, and casual P2P users wouldn't have to reset their connections every time they uploaded files during peak congestion hours.

"ISPs need to figure out how traffic is being distributed among their users," said Larry Roberts, the founder of Anagran, which specializes in helping IP networks manage their P2P traffic. "You can't make money if you're giving the majority of your bandwidth to 5% of your users… the concept that has come forward is that there should be more equality for users based on what they pay for individual usage. I think this is a reasonable and appropriate approach rather than trying to look only at the applications themselves."

Roberts also is one of the designers and developers of the ARPANET computer packet network that evolved into the Internet.
The two kinds of caps most discussed were the kind proposed by Comcast that would slow down individual users' P2P uploads during peak hours, and the kind recently discussed by AT&T that would slap users with overage charges for downloading what the company considers to be heavy amounts of data per month. In their proposals, both companies have made clear that the vast majority of users would not be affected by the cap and that it would only impact users who upload large files such as high-definition movies on a near-constant basis.