IP phone across vpn

[clogz]

Bare with me. I'm the IT guy for this company. The owner got tired of the phone guy and figured phones and computers are close enough. So here's the setup.

3 sites, all on a different class c subnet (I know, not ideal but that was how it was before I got in)

Site A, which is the main office, has an nbx and connects to site B via point to point vpn in the routers. Site B has a pots line and a 3com 3120 IP phone. The phone has a local address from the site B subnet but connects to the ncp at site A, this phone works fine.

Site A also connects to Site C via point to point vpn just like site B. However site C has it's own nbx.

Trying to setup an IP phone at site C like the one at site B. The nbx at site A recognizes the phone and says it is online. However, after the phone downloads and loads the image from the ncp it just hangs displaying the mac address of the phone. Where do I go from here?

 

[engjohn]

If site C already has an NBX, why do you want a Phone at site C connected to the NBX at site A?

I am not sure how well/if this would work.
The NBX uses multicast to update and communicate with the phones. You would have to enable multicast routing for the VPN from site A to Site C. You will also have to seperate the phone from the local Multicast traffic from the local NBX.

If you are just looking to make "free" calls from site to site, you should look at using VTL's. (Virtual Tie Lines).
A VTL will allow you to make calls between NBXs using the VPN.
They are a paid license, but in Rel 6.0.x you get 1 VTL license with each NBX. That is enough to setup your sites and make 1 call. You will need 1 license per call at each NBX.

 

[clogz]

OK, thanks.

 

[synack2]

I agree VTL is probably the better way to do this, but that isn't your problem. What you want to do will work. The reason you only see it get as far as the mac address is most likely that you don't have auto discover telephones enabled in System A. You either have to go to System Wide Setting and enable auto discover telphones, or add the phone manually to telephones in netset using its mac address.