[cisco-voip] DTMF fun

Madziarczyk, Jonathan JMad at cityofevanston.org
Wed Jan 20 15:26:13 EST 2010


Maybe I'm not explaining myself correctly, or I don't understand how it
works...most likely a combination of both.  The link between my CUCM and
the PBX is not H323 to H323.  the PBX thinks the gateway is a DMS100
link, the CUCM thinks the gateway is a H323 gateway.  So I don't know
that the PBX is even capable of understanding H245 signaling, since it's
getting it's DTMF inband at that point.  Does that sound correct?

Having said that I was able to run the debug h245 asn1 on my router,
which does show me whether the DTMF is getting to the h323 gateway or
not.  I guess then next logical step is to see if it is making it to the
VM without being distorted to the point that VM cannot recognize it.



-----Original Message-----
From: Rhodium [mailto:rhodium_uk at yahoo.co.uk] 
Sent: Tuesday, January 19, 2010 5:04 PM
To: VOIP Group; Madziarczyk, Jonathan
Subject: Re: [cisco-voip] DTMF fun

The easiest point for me to start to troubleshoot this would be the
gateway's H.323 connection to the PABX.

CUCM sends DTMF via H245 signal (accepting H245 alphanumeric [AN] only)
so you need to determine what type of DTMF relay your PABX supports?
Does it support H245 Signal or H245 AN.

You can run "debug h245 asn1" to see what type of relay is being used on
the gateway (config dependent) and see whether all the digits are being
sent to the PABX and received from the CUCM. If you are seeing the
correct digits, then you know that the PABX is not accepting all the
digits, if you are not seeing all the digits, the problem is between the
PSTN and your gateway. 

HTH.



      



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