Comcast isn't the only American ISP throttling peer-to-peer file sharing traffic. Cox Communications is pulling exactly the same trick.
According to Robb Topolski - the networking guru who first revealed that Comcast was busting BitTorrents back in May - Cox is using some sort of network hardware tool to sever connections on another P2P service, eDonkey. "I'm seeing the same thing with Cox and eDonkey that I saw with Comcast," Topolski told us.
In essence, Cox is preventing P2P users from seeding files. When one machine attempts to trade a file with another, the ISP is sending a duped "reset flag" to break this peer-to-peer connection.
"At the point where the remote peer asks for a particular section of a shared a file, Cox is sending a forged reset," Topolski said. "This reset is intended to take two peers that are out of sync and get them back in sync. But in this case, the reset is being forged even though there's nothing wrong with the connection."
Previous Topolski tests showed that Comcast is pulling this trick with eDonkey and Gnutella as well as BitTorrent - though it was the BitTorrent bagging that got all the press. Now, he reports that exactly the same interface that plagues eDonkey users on Comcast is hitting users on Cox.
When we asked Cox if this was indeed the case, it tossed us the same canned statement it sent to DSLReports.com, where Topolski's tests were first revealed. Cox reserves the right to "manage" high-bandwidth traffic:
To ensure the best possible online experience for our customers, Cox actively manages network traffic through a variety of methods including traffic prioritization and protocol filtering. Cox does not prohibit the use of file-sharing services for uploads or downloads, or discriminate against any specific services in any way. To help our customers make the most out of their Internet experience, we take proactive measures to ensure that bandwidth intensive applications do not negatively impact their service.
This is a bit easier to stomach than Comcast's initial response to the news that it was bagging BitTorrents. When the story first went web-wide in August, Comcast flatly denied it. The big-name ISP didn't adopt this sort of we're-just-managing defense until last month, when the The Associated Press ran a piece confirming Topolski's tests.
With Comcast, Topolski was able to verify that a network management tool called Sandvine was firing off fake resets, but with Cox, he's yet to zero-in on the specific piece of offending hardware. "I'm not ready to confirm, but I'm 90 per cent sure they're using Sandvine too."
His tests are ongoing, and he also hopes to determine whether Cox is bagging BitTorrents as well as eDonkey swaps. But don't start hounding the guy for answers. He just had a massive tumor removed.
When The Associated Press ran its Comcast story, we phoned Topolski for a comment, but he was in the middle of a nine-day hospital stay. "When the AP story broke, I was out of it," he said. "I don't remember too much."
But now he's cancer-free. And he's back to busting ISPs. ®