[e2e] Skype and congestion collapse.

[Cottrell, Les]

Our measurements are using ping mainly between academic and research sites worldwide. The high losses in the US was several years ago. Typical losses between developed regions of the world (Canada, US, Europe, Japan, Korea, Singapore, Australia/NZ) are << 1%. Things have improved a lot. See for example Figs 3 and 4 of http://www.slac.stanford.edu/xorg/icfa/icfa-net-paper-jan05/.  There are high losses still in parts of the Internet but they are mainly to developing countries (see for example Figs 9 and 10 of the above report).  

-----Original Message-----
From: end2end-interest-bounces at postel.org [mailto:end2end-interest-bounces at postel.org] On Behalf Of Cannara
Sent: Saturday, March 05, 2005 9:43 PM
Cc: End-2-End list
Subject: Re: [e2e] Skype and congestion collapse.

On where congestion is occurring today in the Inet, it would be useful to ask Les Cottrell at SLAC how things have been going with their continued "ping-around-the-world" testing.  It had been true that busy peering points in the East & West of the US commonly lost 30%.

Alex

RJ Atkinson wrote:
> 
> On Mar 4, 2005, at 17:47, Clark Gaylord wrote:
> > This is why we really do need some notion of QoS other than The Fat 
> > Pipe.  It doesn't have to be as elaborate as RSVP-disciplined CAC, 
> > but you need to be able to prioritize traffic that matters and limit 
> > the amount of traffic that gets prioritized.  It doesn't have to be 
> > more complex than that, but it has to do at least that.  [Ergo ... 
> > left as an exercise to the reader.]
> 
> I don't know that the "network" needs to have a more sophisticated 
> notion of QoS than best effort.  It can sometimes be useful for the 
> network device connected directly to a congested link (e.g. access 
> link between a site and its upstream provider) to have some 
> internal-to-the-box QoS configuration.
> 
> It is not uncommon these days for the access router at the customer 
> premise to have some ACL ruleset that prefers some traffic over other 
> traffic or rate-limits certain kinds of traffic -- and equivalent 
> configuration of the aggregation router on the ISP side of the same 
> link is also not uncommon these days.
> 
> That said, most congestion today occurs either on an access link such 
> as that or on some sort of wireless link (e.g. SATCOM to SW Asia).  
> ISP core backbones tend to be over-provisioned.  Most campus 
> (wired/fibred) networks are similarly over-provisioned.
> 
> Ran