Hi there, I've a little issue in my production environment, maybe someone can help me.
Here's the scenario :
The 3845 VG is backhauled by the CUCM 6.1 by means of MGCP.
The VG sees the PSTN by means of a PRI vs. a Siemens HiPath PBX (QSIG trunk).
Users observe that sometimes after calling busy PSTN nunmbers they have to wait more than 10 seconds before hearing the busy tone.
My hypothesis is that in moments of traffic congestion on the PBX, the VGW receiva a "wait until there's a free channel" isdn signal from the PBX (0x8091 - User busy). Is this correct/possible?
I've captured the VG's debug isdn q931 output in both the normal case and the "slow" case (the facility messages are cropped out for space reasons):
Normal behavior (busy tone sent immediately to user) :
*Oct 6 15:22:53.918: ISDN Se0/0/0:15 Q931: TX -> SETUP pd = 8 callref = 0x10DD
Sending Complete
Bearer Capability i = 0x8090A3
Standard = CCITT
Transfer Capability = Speech
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0xA9839E
Exclusive, Channel 30
Calling Party Number i = 0x0081, '4XXXX'
Plan:Unknown, Type:Unknown
Called Party Number i = 0x80, '0XXXXXXXX'
Plan:Unknown, Type:Unknown
*Oct 6 15:22:53.962: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd = 8 callref = 0x90DD
Channel ID i = 0xA9839E
Exclusive, Channel 30
*Oct 6 15:22:53.978: ISDN Se0/0/0:15 Q931: RX <- FACILITY pd = 8 callref = 0x90DD
*Oct 6 15:22:55.258: ISDN Se0/0/1:15 Q931: RX <- FACILITY pd = 8 callref = 0x90D3
*Oct 6 15:22:58.838: ISDN Se0/0/0:15 Q931: RX <- PROGRESS pd = 8 callref = 0x90DD
Cause i = 0x8091 - User busy
Progress Ind i = 0x8088 - In-band info or appropriate now available
Progress Ind i = 0xA090 - Reserved value
---------------------------------------------------------
Slow behavior (busy tone sent to the user after couple of secs) :
*Oct 7 12:21:42.097: ISDN Se0/0/0:15 Q931: TX -> SETUP pd = 8 callref = 0x11C8
Sending Complete
Bearer Capability i = 0x8090A3
Standard = CCITT
Transfer Capability = Speech
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0xA9839E
Exclusive, Channel 30
Calling Party Number i = 0x0081, '4XXXX'
Plan:Unknown, Type:Unknown
Called Party Number i = 0x80, '0XXXXXXXX'
Plan:Unknown, Type:Unknown
*Oct 7 12:21:42.141: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd = 8 callref = 0x91C8
Channel ID i = 0xA9839E
Exclusive, Channel 30
*Oct 7 12:21:42.153: ISDN Se0/0/0:15 Q931: RX <- FACILITY pd = 8 callref = 0x91C8
*Oct 7 12:21:46.437: ISDN Se0/0/0:15 Q931: RX <- PROGRESS pd = 8 callref = 0x91C8
Cause i = 0x8091 - User busy
Progress Ind i = 0x8088 - In-band info or appropriate now available
Progress Ind i = 0xA090 - Reserved value
*Oct 7 12:22:09.969: ISDN Se0/0/1:15 Q931: RX <- DISCONNECT pd = 8 callref = 0x003E
Cause i = 0x8090 - Normal call clearing
*Oct 7 12:22:09.981: ISDN Se0/0/1:15 Q931: TX -> RELEASE pd = 8 callref = 0x803E
*Oct 7 12:22:10.009: ISDN Se0/0/1:15 Q931: RX <- RELEASE_COMP pd = 8 callref = 0x003E
Cause i = 0x8090 - Normal call clearing
*Oct 7 12:22:11.637: ISDN Se0/0/1:15 Q931: RX <- FACILITY pd = 8 callref = 0x91C5
*Oct 7 12:22:16.397: ISDN Se0/0/0:15 Q931: RX <- DISCONNECT pd = 8 callref = 0x91C8
Cause i = 0x8091 - User busy
*Oct 7 12:22:16.413: ISDN Se0/0/0:15 Q931: TX -> RELEASE pd = 8 callref = 0x11C8
*Oct 7 12:22:16.429: ISDN Se0/0/0:15 Q931: RX <- RELEASE_COMP pd = 8 callref = 0x91C8
Cause i = 0x8090 - Normal call clearing
-----------------------------------------------------------
Thanks in advance,
Alberto
