The MPLS WG Archive

[Bora Akyol <akyol@pluris.com>]

>>>>> "David" == David Charlap <david.charlap@marconi.com> writes:


    David> If you need actual QoS guarantees, or if your
    David> switches only support L-LPSs, or if you want the two
    David> service levels to be routed independantly, then you
    David> need to create a separate LSP for each service level.
    David> CR-LDP or RSVP-TE can be used for signalling the QoS
    David> requirements for the two LSPs.


David

You are making assumptions about a particular switch
architecture when you assert that you can not do "actual" QoS
guarantees with E-LSPs. If you have a policer and a
shaper/scheduler that can process the EXP bits as well as the
label, then doing "actual" QoS is quite possible with
E-LSPs. 

Not only that, but you can map traffic destined to the same
prefix to different EXP levels based either on Diffserv bits or
on packet content. This also applies to VLAN tags.

Bora