I have a new install of CUCM 8 running 79xx phones and 10 * 9951 SIP phones
Call routing as follows
inbound calls to a H323 gateway
Outbound calls first to H323 gateway, if fail then next to an MGCP gateway
everything fine with SCCP phones
on the 9951 phone - Inbound calls work fine.
For outbound calls really strange
All calls first routed to the h323 gateway, but on some numbers I get an incompatible destination ISDN error code and then CUCM sends call to MGCP gateway and call completes
On some calls on h323 gateway call seems to setup, but no audio, remote site does not ring and after 17 seconds ISDN drops call.
So in summary calls out via MGCP gateway are ok with 9951 SIP phone
calls out from 9951 SIP phone to H323 gateway do not work.
Cannot change the h323 gateway to mgcp as running a tcl fax detect script
Any help would be great