Vodafone claims line card issue causing video streaming and download problems
The Register has managed to squeeze some information out of Vodafone in relation to the performance problems a number of customers are suffering. The scale of the problem is apparent when you look at our monthly analysis of single download versus multiple download speeds with Vodafone being the worst of the major providers.
We are in the process of upgrading our network configuration and discovered a technical issue with some line cards which means a small number of customers may experience slower speeds when accessing certain sites. This has nothing to do with throttling or traffic management, which we do not use on our broadband service. We are working hard to fix the issue in order to give any customer affected a great online experience. We’re sorry for any inconvenience caused.Vodafone statement on problems to The Register
El Reg ends its story commenting that line cards are usually street cabinet based items, but we know this is not the case since Vodafone don't have any line cards in street cabinets (they use Openreach GEA-FTTC line service). Line cards do exist in core networks, since a good many business grade routers utilise swappable line cards so that the physical interfaces can be changed without having to totally replace very expensive core routers. Another nail in the coffin to the idea of it being street cabinet line cards is that these line cards are shared between users of multiple providers and thus we would expect similar performance problems with offers using the FTTC hardware.
Reading between the lines if this problem has arisen during changes to the network configuration it is possible someone has configured devices in a way that is throttling individual TCP connections which covers most video streaming and a number of other activities. Speed tests and large download tools such as Steam use lots of concurrent TCP connections and thus the throttling of a single TCP connection will not be noticed by many tests or many users (some speed tests use as many as 32 connections at the same time), a handful of speed tests (including our own) do perform a single download test as this is a very good way of spotting whether throttling or some thing else is limiting performance. Of course as many people will default to speed testers that do not do single download testing it is likely that there is a large group of Vodafone users who have noticed something is wrong with video streams and have run a speed test that suggest all is well and thus just blame the internet or swear about a useless Openreach copper network.
Lets hope Vodafone keeps working hard on a solution as this has been a problem for some months, as for why some Vodafone users are affected and some are not it is impossible to say without a lot more detail on how their core network is segmented and exactly what upgrades are underway.