[j-nsp] <COS Query> While imposing MPLS labels what value is set on EXP bits

[Amarjeet Singh]

Folks - I've query on COS in MPLS VPN environment.

While receiving Packets ingress from CE, let's say TOS field in IP header
is set to IPP-4.
And i've a MF that is classifying IPP-4 into FC-4 + PLP-LOW.
+ There is MPLS Rewrite rule on egress interface that is matching
FC-4+PLP-low and setting EXP bits to 4 (100)  while relaying packet to next
hop.

EXP rewrite happens only on MPLS encapsulated packets before that packet
should be MPLS encapsulated first.

 While receiving IP packets coming from CE and imposing 2 Label stack on it
(Transport/VPN label) what value is set on EXP bits of Labels? Does the TOS
value in IP header of IP packet is copied to MPLS EXP bits?

How does the MPLS classification happens to set FC+PLP on MPLS packets
before hitting MPLS EXP rewrite rule on egress?

Much Appreciated.

Br, Amarjeet