We have configured one SIP trunk between CUCM v6.0 and NEC SV8100. Calls from NEC PBX to CUCM (via SIP trunk) are working fine, but calls from CUCM to NEC can´t establish, they are rejected by NEC PBX with a SIP code "SIP/2.0 486 Busy Here". MTP required box is checked and we are using G711alaw codec in this trunk. I attach two traces, one trace is originated from CUCM and other one is originated from NEC PBX and it is working.
Has anyone configured this SIP trunk between CUCM v6.0 and NEC SV8100? do you know if there is any guide that can help me?
Thanks in advance.