Trouble with a new H323 Gateway installation and ISDN

[alalli]

Hi All,

I am having trouble getting calls in/out of an H323 gateway connected to a partial ISDN service.

I have attached a debug and a router config.

If someone can have a look and see if they see anything drastically wrong, that would be most appreciated.

When I use the csim start command to dial out,  I get an error message saying that the resource was unavailable.

When I try to dial into the router from outside,  I can see the call hitting the router ISDN interface, but I get a network congested error message.

Thanks in advance for any help.

Regards

amanda

[mdawar]

Hi Amanda

Did you tried reloading the router?

[phooghen]

Looks like a Telco  issue.

Pierre.

[iptuser55]

I could not open the zip files but do the number of channel match up  i.e have you configured the same number of channels in H323 as in the Telco?. Maybe a quick check is to change the order so from bottom up to top down or the other way round???

[Steven Holl · Accepted solution]

Doesn't look like a telco issue.  The gateway is sending the disconnects:

*Jan  6 07:17:21.492: ISDN Se0/0/0:15 Q931: TX -> DISCONNECT pd = 8  callref = 0x0086
Cause i = 0x80AF - Resource unavailable, unspecified

...

*Jan  6 07:18:01.056: ISDN Se0/0/0:15 Q931: TX -> RELEASE_COMP pd = 8  callref = 0x8017
Cause i = 0x80AA - Switching equipment congestion

Is this for every call?  You may be running out of DSPs.  Or you could be hitting CSCsx67255 - ISDN Call Failure w/ cause 47 after DSP Allocation Failure.

You'd need to really run h225 asn1 and h245 asn1 debugs in parallel with voip ccapi inout and q931 debugs to diagnose what's happneing on the voip leg.  Also glance at 'sh voice dsp group all' and make sure you have enough flex credits for TDM calls.

And I wouldn't test with 'csim start' for something like this.  It doesn't always behave as it should.

[alalli]

Thank you all so much for your replies.

The fault turned out to be a faulty DSP chip.

show voice dsp group all showed that the dsp did not load correctly in spite of reloading the router.

Once the router had a working DSP,  it worked fine.