[c-nsp] mls qos on 7600 with native vlan and MPLS

[Ольга Ружанская]

Hello,

> My understanding is that this queueing mode can be based only on COS 
> field on GE and 10/100/1000 line cards. So what will be the router 
> behaviour if there is no 802.Q and therefore no 802.1p
During processing, PFC QoS represents the priority of all traffic (including non-IP traffic) with an internal DSCP value. On the PFC, before any marking or policing takes place, PFC QoS derives the initial internal DSCP value as follows: 
 From received CoS values or from port CoS values for trust CoS traffic. 
 Mapped from received IP precedence values for trust IP precedence traffic. 
 From received DSCP values for trust DSCP traffic. 
 Mapped from port CoS or DSCP values configured in policy maps for untrusted traffic. 
For all egress traffic, PFC QoS uses a configurable map to derive a CoS value from the final internal DSCP value associated with the traffic. 

> I do run MPLS in the core for VPN services. The core interfaces are 
> in mode "no switchport" and are untagged as well (routed ports on 10GE 
> interfaces). Here too, what happens if I have cos based queueing (as 
> this is native ethernet)? What happens if I run DSCP based queueing (as 
> this is MPLS, can dscp be used?) My goal here is more to make sure that 
> my qos does not break anything.
For received Layer 3 MPLS packets, the PFC usually trusts the EXP value in the received topmost label. None of the following have any effect on MPLS packets: 
 Interface trust state 
 Port CoS value 
 Policy-map trust command 


Actually, there are a lot of information. I hope that these links will be usefull:
1) http://www.cisco.com/en/US/docs/routers/7600/ios/12.2SR/configuration/guide/qos.html
2) http://www.cisco.com/en/US/docs/routers/7600/ios/12.2SR/configuration/guide/mplsqos.html

Best regards,
Olga.