MPLS EXP bits in FRoMPLS

[Adrian Chovan]

Hi,

i am setting up FRoMPLS connection using a pair of 7200VXR with IOS 12.2(33)SRE5. I need to copy the TOS values from the tunneled IP header into the EXP bits of the MPLS label(or even better, set the EXP bits using the DSCP values of the IP header). At this moment i am not able to accomplish this task, i only found a way to do this using L2TPv3. The only QoS marking of the MPLS labels for FRoMPLS i found is using the DE bit in the FR header which is not what i need. I need to finish this task as quickly as possible, any advice will be highly appreciated.

Thanks,

Adrian

[Peter Paluch]

Adrian,

As much as I would like to help, I am afraid that what you require is not directly supported. I assume you are using a xconnect-style of provisioning a pseudowire between two Frame Relay-attached customers (an AToM deployment).

Would a conversion into L3 VPN with FR attachment between CE/PE be an option? That would then allow you to use the ordinary MQC to manipulate the MPLS TC (formerly EXP) bits.

Best regards,

Peter

[Adrian Chovan]

Hi Peter,

the L3 VPN is not applicable in this case, tunneling transparent from the customers view is required. At this moment i found the way to provision differentiated quality of service for specific traffic coming from FR circuits based on DLCI using tunnels with defined QoS marking. However, this requires changes in the configuration of the CE device which is what i tried to avoid and the overall complexity and maintainability of the configuration becomes relatively high.

I am a little disappointed that there is no direct support for this application, allthough the standards do not directly require it. For me, this represents a big drawback of any AToM deployment compared to L2TPv3 for FR or ATM tunneling, this feature is supported for Ethernet pseudowires based on 802.1p marking only(there is also no support for class based tunnel selection in AToM, which i consider higly disappointing too). I am a big fan of Cisco and its technology support, but for example Huawei, which usually delivers much less sofisticated equippment, does support both of these features.

Adrian

[Peter Paluch]

Hi Adrian,

Sounds like good ideas for enhancement indeed. Anyone from Cisco to comment on this?

Best regards,

Peter