<p>Having never used RSVP but after reading up on it I think it might solve an issue I'm looking at.
A (non Cisco) IPT installation uses either G.711 or 729 codecs, either can be selected depending on the number of licencies available. I've been asked to provision the QoS.
On the PBX CAC seems the solution to control the number of calls across a link, and I think it will signal the bandwidth required using RSVP. But, the notes I have on CAC all talk about using RSVP with voice gateways, which are not used in the network I'm looking at.
The IP phones use RTP, will a router configured for RSVP with the LLQ option automatically detect the RTP flow, or do I have to classify this somehow?
I started looking at NBAR for classifying based on codec in use, for a Diff Serv type QoS implementation, then came across CAC and ended up looking at RSVP, now I'm confused.</p>