[c-nsp] ASR9000 MPLS QOS Issue

[Xu Hu]

Hi Team,

Recently test the QOS in MPLS network occur one issue.

CE---PE-1----P----PE-2----CE.

CE and PE just running static route, PE and P running OSPF for IGP, MP-BGP,
then also LDP and MPLS/TE auto-tunnel.
In the input direction of PE-1 towards CE side, i match the DSCP value CS6,
then reset the value to CS5.
In the output direction of PE-1 towards P side i match the DSCP value of
CS5 also match the MPLS EXP 6 in one class-map.

The issue is in the output direction if PE-1 towards P, i cannot match the
DSCP value, but can match the EXP 6 (DSCP value CS6=EXP 6), i don't know
why the reset DSCP value cannot work, because if the reset works, then the
EXP 6 should not matched, DSCP value CS5=EXP 5.

Also i don't know how the PE-1 router trust the QOS value, it will choose
the DSCP value or MPLS EXP value?
If in the same class-map, i match DSCP value and also MPLS EXP value, how
the PE-1 Router choose? Which one will trust?

I understand maybe this is a MPLS/VPN QOS design issue, will appreciate for
any comments about this.

Best Regards,
Hu Xu