IP QoS case-studies

Mon Feb 3 22:31:01 UTC 2003

Pete,

Our network is currently offering DiffServ QoS to customers.  It's a new
service, but so far it is working well and has been very well received
by our customers.  

I'd be happy to answer any questions about what we do or why offline but
here are some "talking points" of our policy.

1.  We established a network wide delay budget and then put together
some software that monitors network latency.  

2.  We control the classification feature.  We classify all our customer
traffic for them with Cisco class based policing at the CPE router.  

3.  We use Cisco's LLQ or MDRR queuing only on our links from
distribution to the network edge.   On our high speed links (622Mb and
above) we don't queue.  There are two schools of thought on this, but we
currently subscribe to the theory that just letting FIFO happen is
faster than applying custom queues in the core.  YMMV with very fast
routers, ASICs, and all that.

Hope that helps!

Mike

-----Original Message-----
From: Pete Kruckenberg [mailto:pete at kruckenberg.com] 
Sent: Monday, February 03, 2003 1:04 PM
To: nanog at merit.edu
Subject: IP QoS case-studies

I've found there's no shortage of advice and theory about
the viability of IP QoS (DiffServ) in a large wide-area
(converged) network.

I have not had much luck with finding documentation about
experiences implementing and operating such a beast.  
Presumably that's yet another (silent) confirmation that It
Doesn't Work or There's a Better/Easier Way.

Nevertheless, I'd still like to find anyone who has tried
(successfully or not) to converge (ie VoIP/H.323/data) a
high-speed (~ 1Gb/s) IP network and use IP QoS for what it
is sold to do. White paper/presentation references or
off-line conversation would be appreciated.

Pete.