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qos on access (Re: is this like a peering war somehow?)

  • From: Mikael Abrahamsson
  • Date: Mon Jan 23 07:04:23 2006

On Mon, 23 Jan 2006, Todd Vierling wrote:

Provided that IPTV or VoIP are the only [large] datagram streams in progress, this is not difficult to do on the CPE end -- in fact, this sort of thing is already available as a QoS option in some home router appliances. It involves scaling back TCP streams so that they leave enough headroom for the in-progress IPTV or VoIP.
Doing QoS on the CPE side of the access link is always risky, you can't really create any guarantees there since it's already "too late", you're not the one doing the buffering. Especially since a lot of L2/L3 DSLAMs don't have a lot of buffers (40ms on ADSL2+ 24meg in one of my tests), you really have to strangle TCP in order to guarantee that you TV packets aren't dropped.

--
Mikael Abrahamsson email: swmike@swm.pp.se