[c-nsp] RSVP QoS, CAC and HQF

tkacprzynski at SpencerStuart.com tkacprzynski at SpencerStuart.com
Tue Jul 2 11:36:58 EDT 2013

I'm working on setting up RSVP Call Admission Control for Cisco's call manager. I have the CAC working nicely, but my problem is with ensuring that the reserved bandwidth will actually get queuing reservation in the data plane. So my question is not voice specific but rather RSVP with DiffServ.

After Cisco implemented HQF in 12.4(20)T they change the Weighted Fair Queuing to Flow-based Fair Queuing, which treats each flow equally. RSVP used to have a special reserved queue with a very low weight attached to it.  This low weight provided for preferred queuing. From what I have read RSVP does not do any classification of RSVP reserved packets, but is only a control protocol. If I were to use a LLQ to select only EF traffic for voice and have RSVP signal the reservation, how do I prevent other EF traffic from coming into that LLQ? Do I have to do it manually? Is there any sort of RSVP classification with HQF that will put flows matching reserved with RSVP into a special queue?

Thank you for any help on this matter.

Tom Kacprzyński

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