[c-nsp] ASR9000 MPLS QOS Issue

[Saku Ytti]

On (2012-07-11 18:06 +0800), Xu Hu wrote:

> Yes, you are right, now my big concern is that if one packet have one DSCP value, then after transfer through the MPLS network (deploy the MPLS EXP QOS in the MPLS network) the output packet will attach the same DSCP value or not?

Both are supported. Uniform mode where it is DSCP -> EXP, EXP -> DSCP. And
Pipe mode where in ingress you set EXP was you wish and in egress you can
schedule based on EXP, without writing it in DSCP.

I.e. Pipe mode retains original DSCP, not mangling it, not necessarily even
using it. Uniform mode transports DSCP as EXP.

I personally would always do Pipe mode as Core QoS and Access QoS are two
different things.
In Pipe mode depending on platform, you store EXP in internal DSCP or copy
it via QoS config to 'qos-group' in MPSL2IP and then in IP egress, you
schedule based on qos-group value. ASR9k does support qos-group, so I would
suggest using them.

-- 
  ++ytti