Problem with voice call setup between 1760 and MC3810

[linas]

Situation is next: It is impossible to make voice call (vofr) from C1760 to MC3810.

1. Call from MC3810 to C1760 goes fine, except there is no alerting signal. Connection uses G729ar8 codec.

2. Call from C1760 to MC3810 fails – congestion tone is heard.

3. Call from C1760 to C2611 and vise versa goes absolutely fine !!! C2611 is central enterprise Frame Relay router and MC3810 and C1760 – branch‘es routers.

4. C1760 is upgraded to newest 12.3.(2)T version.

5. WE don‘t want to upgrade MC3810 flash and ram memory in order to upgrade MC3810 IOS to newer version , because budget doesn‘t allow these expenses.

What could be a problem ?

C1760 has image c1700-sv3y-mz.123-2.T.bin

IP/VOICE PLUS

MC3810 has image mc3810-is-mz.121-4.bin

[sbilgi]

The following document might help you :

http://www.cisco.com/en/US/tech/tk652/tk701/technologies_tech_note09186a0080093f5e.shtml

[mhayek]

If you are using voice-encap on the 3810, then make sure you are also fragmenting on the 1760 side.

These should be compatible in most cases, there are some incompatibilites when using voice-encap with FRF12 fragmentation.