UPD2 Virgin Media Broadband Users Hit by Peak Time Congestion and Latency

Customers of UK cable operator Virgin Media have spent the past few days suffering from a mix of above normal latency and network congestion during peak times (late afternoon/night), which occurred after one of the ISPs public peering providers, Atrato, switched most of its traffic flow to the ISPs disadvantage (i.e. changed their routing).

The situation, which began around the middle of last week and has been affecting services across the country (other ISPs may also have been hit), resulted in customers experiencing a mix of slow speeds and high pings. The latter in particular made some online services, such as fast-paced multiplayer games, extremely difficult to use.

It didn’t take long for our inbox and a related topic on Virgin’s Community Forum to fill with complaints. Many customers were clearly very angry at the provider’s inability to recognise the problem until this afternoon. The following statement has now been posted.

Mark Wilkin, VM’s Help & Support Forum Manager, said:

“We’ve identified an issue with our peering links to a company called Atrato who we publically peer with in Amsterdam and London. They were pushing abnormal amounts of traffic through our public peering links at LINX, overloading them. So we’ve shut down both of our peering links to Atrato at LINX which should resolve this issue.

Meanwhile we’re going to continue to investigate the root cause of this problem..”

The operator has separately informed ISPreview.co.uk that it took time for Virgin Media to identify who has moved what traffic to where on their shared public sessions. On top of that we understand that Atrato wasn’t helping matters by being equally slow to communicate and do the necessary traffic engineering.

Instead of waiting for Atrato to resolve the problem at their end Virgin has alternatively chosen to shut down their two LINX (London Internet Exchange) sessions and thus force the traffic back through either Amsterdam or onto Transit (note: they shut down the Atrato links for their peering not the LINX network itself). It’s hoped that this should result in some improvement tonight but the ISP will keep monitoring and has promised to issue us with a more official statement in due course.

UPDATE 16th October 2012

Performance last night seems to have been much improved for practically everybody we spoke with this morning, although some still claimed to be experiencing issues and others on Virgin’s forum felt that latency was better but not as good as it has been before the issue began. This makes sense as Virgin Media will be waiting for Atrato to resolve their peering problems before switching traffic back from the temporary solution.

UPDATE 16th Oct (11:10am)

A spokesperson for Virgin Media just told us that they now believe their “workaround has fixed the issue“, although they’re still unsure why Atrato changed their routing in the first place.