[c-nsp] ATM QOS

[Nassess, George (Contractor)]

Hello, 
 
I posted part of this question a while ago but no hits. Since I
understand better and can describe it better, I figured I'd try again. 
 
I have a large multisite ATM network running across two metropolitan
BLSR Sonet rings connected by a long haul BLSR sonet ring in between to
create one large ATM network. I need to setup end-to-end QOS initially
between two of many sites on the ATM network to support IP Trunking
between PBXs at different sites for failover and overflow of voice
traffic. Eventually QOS will need to be end-to-end for all sites, and
eventually we will probably get rid of ATM alltogether and just use all
switched optical links.  
 
I have Site A that needs QOS to site C. Sites A,B, and C all connect to
their local ATM switch with an OC3 Interface. Site C and site B have ATM
switches connected by an OC3 link. Site B and Site A have ATM switches
that are only connected by a DS3 link.
 
So this DS3 is a bottleneck for this traffic. I can create a service
policy to prioritize and police traffic as it is put onto the ATM
network, but I have not been able to determine how (and Cisco TAC has
not been able to advise how) to get the ATM switch network to see some
type of marking and apply some sort of priorty queueing or other QOS
mechanism to avoid congestion for our voice traffic from site A to C
without being impacted by any heavy traffic between site A and B. 
 
For our offices that run LANE I can place the appropriate traffic into a
UBR+ queue to prioritize, but noone can seem to be able to explain how
to use any similar mechanism for traffic placed onto the ATM network by
a routed interface that will be honored further downstream on the ATM. 
 
 
Thanks in advance for any assistance, 
 
Gus Nasses
Network Analyst