[c-nsp] mpls-te - dynamic latency?

[Aaron Daubman]

Christian,

> it just yet, But the end goal (whether it's that feature or not) is that
> we'd the tunnel to be as visible to the routing
> protocol as poss (autoroute i guess) and be routing traffic into those
> tunnels based on dscp markings. If I can
> avoid 'invisible' mechanisms like pbr, than I will.
>
> Also, it's not just a matter of making sure the low latency path is
> chosen, but that non-latency-dependent traffic
> will use the other link.
>
> As for using the affinity bits, cheers, I'll look more into that.

Depending on your IOS version in use, you might get a great deal of
benefit from using MPLS Traffic Engineering Class Based Tunnel
Selection:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1829/products_feature_guide09186a00802659b9.html
"""
Multiprotocol Label Switching (MPLS) Traffic Engineering (TE)
Class-Based Tunnel Selection (CBTS) enables you to dynamically route
and forward traffic with different class of service (CoS) values onto
different TE tunnels between the same tunnel headend and the same
tailend. The TE tunnels can be regular TE or DiffServ-aware TE (DS-TE)
tunnels.

The set of TE (or DS-TE) tunnels from the same headend to the same
tailend that you configure to carry different CoS values is referred
to as a "tunnel bundle." After configuration, CBTS dynamically routes
and forwards each packet into the tunnel that

•Is configured to carry the CoS of the packet

•Has the right headend for the destination of the packet

Because CBTS offers dynamic routing over DS-TE tunnels and requires
minimum configuration, it greatly eases deployment of DS-TE in
large-scale networks.

CBTS can distribute all CoS values on eight different tunnels.

CBTS also allows the TE tunnels of a tunnel bundle to exit headend
routers through different interfaces
"""

Regards,
     ~Aaron