09-29-2008 07:50 AM - edited 03-15-2019 01:36 PM
Hello,
I have 28xx and 5350 routers with E1 cards, acting as Voice Gateways, converting from SIP to Q931.
(124-16b IOS).
I have the following problem:
1) Inbound call on the Q931 interface (SETUP)
2) SIP INVITE sent by VGW to customer SIP Endpoint
3) Endpoint replies with 100 Trying
4) VGW sends Call Proceeding and Progress via Q931
5) Endpoint sends 486 User Busy
6) VGW ACKs the 486
7) VGW sends DISCONNECT via Q931
The problem I am having is that between steps 6 & 7 there is a 10 second delay. There is no delay on the SIP leg of the call (from INVITE to ACK takes 0.17 seconds) so it seems that the VGW is not acting on the 486 for 10 seconds.
Has anyone got any suggestions regarding this problem?
Any help would be much appreciated
Regards
Richard
------------------------------------
Q931 trace
15:47:45.833 BST: ISDN Se0/1/0:15 Q931: RX <- SETUP pd = 8 callref = 0x001A
Sending Complete
Bearer Capability i = 0x9090A3
Standard = CCITT
Transfer Capability = 3.1kHz Audio
Transfer Mode = Circuit
Transfer Rate = 64 kbit/s
Channel ID i = 0xA9839B
Progress Ind i = 0x8581 - Call not end-to-end ISDN, may have in-band info
Calling Party Number i = 0x21A3, '7825123456'
Called Party Number i = 0x81, '0207123456'
15:47:45.861 BST: ISDN Se0/1/0:15 Q931: TX -> CALL_PROC pd = 8 callref = 0x801A
Channel ID i = 0xA9839B
15:47:45.861 BST: ISDN Se0/1/0:15 Q931: TX -> PROGRESS pd = 8 callref = 0x801A
Progress Ind i = 0x8188 - In-band info or appropriate now available
15:47:56.150 BST: ISDN Se0/1/0:15 Q931: TX -> DISCONNECT pd = 8 callref = 0x801A
Cause i = 0x8091 - User busy
10-03-2008 12:45 PM
Cause i = 0x8091 - User busy.
This is because the called system acknowledges the connection request. However, the system cannot accept the call because all B-channels are in use. The user equipment is compatible with the call in this situation.
If you have multiple ISDN circuits, the telco can configure them in a "hunt-group", in which calls switch to the next available circuit.
10-09-2008 05:47 AM
Hi,
Thanks for your comments on this issue, however this does not answer the question.
The Q931 "user busy" is being generated due to the SIP "486 User Busy", rather than a limitation on B-channels.
My question is; why does it take 10 seconds from the VGW receiving the 486 until it sends the Q931 user busy?
Regards
Richard
06-22-2009 12:58 PM
try: voice call disc-pi-off
Check out this thread:
https://www.myciscocommunity.com/message/8500;jsessionid=28E66AE8AFC5C68EB9D1DAB031806004.node0
06-22-2009 07:23 PM
Hi Richard,
I would do this:
debug voip ccapi inout
You'll see 2 large 'gaps' in the output with things like:
----------------something-----------
ciscoani=1234
cisco....
cisco...
cisco.....
ciscodest=5551234
(info info info incoming dial-peer=x ..........)
Those are the call legs being established. You will see the incoming dial peer directly below that for the pots dial peer and the outgoing dial peer for the SIP leg for the second.
My guess is that you'll see some more with the same ani/dest because your IOS may be hunting for other solutions.
Because otherwise, I don't know of a good reason for this delay to be there. It may be trying to send it out another dial peer that it just can't contact and it's waiting for the TCP SYN timer to pop.
-nick
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