I have bit strainge problem, When user sends fax to PSTN trough MGCP router and if FAX on PSTN network is busy , MGCP gateway is receiving incorrect ISDN cause code '47 ' "resource unavailable "instead of 17 - Busy on ISDN q931 debug on MGCP router. It seems MGCP router is getting incorrect isdn cause code from telco. I have posted Debug example when PSTN fax was busy.
Sep 14 06:35:51.629 UTC: ISDN Se0/0/0:15 Q931: TX -> SETUP pd = 8 callref = 0x644A
Bearer Capability i = 0x8090A3
Standard = CCITT
Transfer Capability = Speech
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0xA98399
Exclusive, Channel 25
Calling Party Number i = 0x0083, N/A
Called Party Number i = 0x80, '62932782'
Sep 14 06:36:12.725 UTC: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8 callref = 0x644A
Cause i = 0x80AF - Resource unavailable, unspecified
Sep 14 06:36:12.785 UTC: ISDN Se0/0/0:15 Q931: TX -> RELEASE_COMP pd = 8 callref = 0x644A
This issue is not happening for Internal FAX .
Any suggestions to resolve the issue ? any commands to map ISDN Cause code to busy ??