Callmanger and low speed connection remote sites

[kpap]

I have Callmanager 3.1.2c on the central site and 20 branch offices connected via low speed 64 or 128 kb/s leased lines. I need to use 7960 ip phones on the branches to talk all over the WAN and use 1751-V as local voice gateways to the PSTN public network. It's easy to configure a different codec to talk over WAN and LAN ? I need it to have a call capacity of 4 calls through WAN links. How do I can do that ?

[rickb]

Basically, you need to setup locations and regions. A good explanation can be found here:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_administration_guide_chapter09186a00800c4c82.html

I would setup one for the hub and one for all the spokes and use G.729 between them.

You are going to be hard pressed to get 4 calls across a 64kbps link with any sort of quality. Look into "ip rtp-header-compression" as well.

Rick