[cisco-voip] Intermittent call failure on QSIG trunk

[afatsum]

 Also make sure that you are not creating a loop between your gateway 
and PBX. A loop will eatup all the channels suddenly and next call will 
get busy signal until a channel is freed for the call. As Wes said, the 
q931 debug will show you more details, in case of a loop you will see 
quick increment in channels within debug messages.

One way to prevent the loop on your cisco side gateway is to make sure 
that incoming calling search space on the gateway does not contain the 
path back to the other PBX.

Musfa


Wes Sisk wrote:
> If you can capture the q931 debugs that show the requested 
> circuit/channel you can have a much more focused discussion with the 
> pbx tech.
>
> /Wes
>
> On Thursday, October 15, 2009 3:25:51 AM, Sechaba Mokoena 
> <sechabam at gmail.com> wrote:
>> Hi Wes,
>>
>> The B-Channels on my router are all in service, the only problem is 
>> that I don't have visibility on the Alcatel PABX, we are making 
>> arrangements with the vendor to investigate. We have access to all 30 
>> channels on the PRI from what I understand. We'll have a look at the 
>> channel selection order on the Alcatel PABX. Thanks for the assistance.
>>
>> Kind regards,
>>
>> Sechaba Mokoena
>>
>> On Wed, Oct 14, 2009 at 4:39 PM, Wes Sisk <wsisk at cisco.com 
>> <mailto:wsisk at cisco.com>> wrote:
>>
>>     So either an invalid channel was selected or one was selected
>>     that was already in use.
>>     invalid channel - only reason this typically happens is that
>>     B-channels are taken out of service. Are the b-channels out of
>>     service for some reason? is this a fractional PRI where only some
>>     b-ch are used?
>>     already in use - this is called "collision" and is usually
>>     mitigated by using opposing channel selection order on the CO and
>>     provider equipment.  One does top down, the other bottom up.
>>
>>     observing 'debug isdn q931' for a while prior to the error would
>>     allow you to track the state of things and clarify why the error
>>     is happening.
>>
>>     /wes
>>
>>
>>     On Wednesday, October 14, 2009 10:27:29 AM, Sechaba Mokoena
>>     <sechabam at gmail.com> <mailto:sechabam at gmail.com> wrote:
>>>     Hi,
>>>
>>>     I have a 3825 router connected to a Siemens HiPath PABX with a
>>>     QSIG. My Cisco IP Phones place calls to the PSTN though the QSIG
>>>     trunk. I've been having intermittent errors with placing calls
>>>     through the trunk, and I've picked up the following error
>>>     through debugs:
>>>
>>>     **ERROR**: CCPMSG_OutCall: fails with cause 0x22
>>>     Cause i = 0x80A2 - No circuit/channel available
>>>
>>>     I don't think its over utilization, I checked the channels in
>>>     use and only a third were active. Does anyone know what could be
>>>     causing this.
>>>
>>>     Kind regards,
>>>
>>>     Sechaba Mokoena
>>>
>>>     ------------------------------------------------------------------------
>>>
>>>     _______________________________________________
>>>     cisco-voip mailing list
>>>     cisco-voip at puck.nether.net <mailto:cisco-voip at puck.nether.net>
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>>>       
>>
>>
>
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