[c-nsp] QoS possible on the 7600 Sup720-3bxl?

[Jose]

Hi everyone.  I've been having a hard time with myself and with Cisco's 
help in trying to setup some kind of QoS on our 7609 distribution routers.

In a nutshell, what I'm trying to do today is to mark all of our 
customer's internet traffic that comes into the 7609 with an EXP bit of 
1.  From there, it will head towards our core router(s) and we would 
prefer to be able to assign this traffic into the Best Effort queue that 
we create on the egress interfaces.

At first I thought this would be as simple as creating a policy-map that 
matched on everything and setting it to experimental 1 for the ingress 
traffic.  For the egress I could match on experimental 1 and forward it 
on.  However, I'm finding that this is not so simple on the 7609.

The first problem that arose is that setting the EXP bit to 1 on the 
ingress traffic manages to change the IP Precedence for the packets if 
the traffic is destined to another customer hanging off the same 7609 as 
the customer originating the traffic.  So if it's CE-->--PE-->--CE and 
the first customer is sending IPP 5 the second CE is receiving the 
traffic as IPP 1 because of the "set" command on the PE's 
sub-interface.  This presents a problem as we don't want to remark any 
of our customers' IPP/DSCP traffic.

The second problem we ran into is that assuming we ignore the above 
problem, we were not able to match on EXP 1 for the egress traffic as 
I've recently found out that the 7609 can only match on packet values 
that exist before it enters the router.  Apparently this means that I 
would have to match on IPP/DSCP for our customers' traffic entering the 
7609 so that it can be put into the appropriate queue for egress.  
Matching on the EXP bit does nothing and so that part of the policy-map 
is ignored and traffic goes into the default-class queue.

So my problem now is that I have to come up with some method of tagging 
all of this internet bound traffic so that it goes into the appropriate 
queue.  One solution that I thought of was setting the EXP bit for all 
internet bound traffic on the egress port.  While this solution worked 
in that the P core router was seeing all of my traffic as EXP 1, I am 
not able to use any kind of queueing mechanism such as LLQ or CBWFQ on 
the egress ports.

Now at this point I'm stuck and no longer know what to do.  Can anyone 
offer any suggestions or workarounds?

FYI, here are the details with the box I'm working with:

SUP720-3BXL
12.2(18)SXD4
OSM-2+4GE-WAN+
Router is an Internet PE with full routing table and no VRFs

I'd offer to put on the policy-maps I was using but it seems kind of 
irrelevant since they don't seem to work.  But if you guys need them let 
me know and I'll post them.

Thanks!

Jose