I have two serial interfaces on a 3925 configured as QSIG trunks connecting to a Nortel Meridian. The config for each interface is given below. There are 23 B channels plus 1 D channel on each trunk. But according to the debug isdn q931, I see calls taking Channels 30 and 35? What gives?
interface Serial0/0/2:23
description To-Nortel-Loop-6
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable
interface Serial0/0/3:23
description To-Nortel-Loop-7
no ip address
encapsulation hdlc
isdn switch-type primary-qsig
isdn timer T310 120000
isdn protocol-emulate network
isdn incoming-voice voice
isdn bind-l3 ccm-manager
no cdp enable
Jul 8 17:30:35.408: ISDN Se0/0/2:23 Q931: TX -> SETUP pd = 8 callref = 0x7AC2
Sending Complete
Bearer Capability i = 0xA880
Standard = ISO/IEC
Transfer Capability = Unrestricted Digital
Transfer Mode = Circuit
Transfer Rate = Packet - not specified
Channel ID i = 0xAC
Exclusive, Channel 35
Facility i = 0x9FAA06800100820100A11802025CD7020151300FA50A0A0100120536393533300A0120
Calling Party Number i = 0x0081, '42'
Plan:Unknown, Type:Unknown
Called Party Number i = 0x80, '9530'
Plan:Unknown, Type:Unknown
Jul 8 17:30:35.476: ISDN Se0/0/2:23 Q931: RX <- CALL_PROC pd = 8 callref = 0xFAC2
Channel ID i = 0xAC
Exclusive, Channel 30
Jul 8 17:30:35.516: ISDN Se0/0/3:23 Q931: RX <- SETUP pd = 8 callref = 0x0E38
Sending Complete
Bearer Capability i = 0xA880
Standard = ISO/IEC
Transfer Capability = Unrestricted Digital
Transfer Mode = Circuit
Transfer Rate = Packet - not specified
Channel ID i = 0xAC
Exclusive, Channel 35
Facility i = 0x9FAA06800100820100A11802025CD7020151300FA50A0A0100120536393533300A0120
Calling Party Number i = 0x80, '42'