in some cases yes - ATM based DSL lines are particularly bad at coping with VoIP under congestion - I presented some stats from my days at COLT on this at UKNOF4 I think.
However even with QoS and other priority chaos there is still no guarantee even on IP friendly access links. Sent from my iPad On 7 Jun 2012, at 16:10, "Christian de Larrinaga" <[email protected]<mailto:[email protected]>> wrote: Neil Do you find the model of asynchronous links to premises makes it tougher for everything to get "enough bandwidth" ? Christian On 7 Jun 2012, at 15:05, Neil J. McRae wrote: IP networks 101. If you have enough bandwidth everything gets a good deal. Sent from my iPhone On 7 Jun 2012, at 10:42, "Justin Finkelstein" <[email protected]<mailto:[email protected]>> wrote: nteresting; so it sounds, from what you say, that by default VoIP gets a "good deal" out of the available bandwidth? On 7 June 2012 09:55, Adrian Kennard <[email protected]<mailto:[email protected]>> wrote: On 07/06/12 09:45, Justin Finkelstein wrote: > > This may be the wrong forum for this message, but I was wondering about > how VoIP is handled as part of people's various traffic shaping policies > - i.e. is this something people take account of? Our LNSs know the rate of every line, and shape to match the line rate but with small packets having more priority over large - this works well for VoIP, but also ACK packets, DNS, interactive (key strokes), etc. We find people can fill their line with torrents and still have perfect VoIP calls. > Also: if one of the UK's ISP's decided to implement QoS on their > customer base's users and then prioritise VoIP, what kind of impact > would this have on the upstream network? Upstream is not usually an issue as it is not usually congested!
