DTMF and Symmetric NAT

Grahame · 02-05-2008, 10:36 AM

Having recently experienced some voice quality problems with a couple of Providers, I followed the post " How to Improve Your Voice Quality ".

I changed my settings as per the post i.e symmetric NAT NO, Optimise Audio YES and indeed call quality did improve.

However, I now find DTMF is not being recognised if I make calls to numbers which require " Press 1 for Sales etc ".

I have changed back to symmetric NAT Yes and Optimise Audio No and all works perfectly.

Why would the NAT setting block DTMF ? Any help gratefully received.

Best regards

Grahame

green · 02-05-2008, 12:07 PM

I suppose this issue is not related to NAT directly.
Just try to change DTMF settings (rfc2833 vs SIP INFO) on your side and check the result.

Grahame · 02-05-2008, 07:47 PM

Thanks for the reply.

I'm set on my side to RFC 2833 ( default ). The only changes I can make are to PCM or SIP INFO.

Did you mean change to SIP INFO ?

Grahame

ctylor · 02-06-2008, 02:28 AM

yeah, try changing those DTMF settings to one of the other two when you have the audio optimized; it might work better

Update: I imagine it could be anything. It would take a network engineer and a fat wallet to ever truly get to the bottom of various bugs in the system. Glad to see it was easily resolved.

Grahame · 02-06-2008, 10:11 AM

I have reset Symmetric NAT to No and Voice Optimisation to Yes.

I have tried DTMF as PCM or SIP INFO on my ATA ( ZyXel P2002L ) and IVR calls work fine using either.

Why this should work and RFC 2833 does not I have no idea.

Many thanks for your help

Best regards

Grahame

02-05-2008, 10:36 AM	#1
Grahame Member Join Date: Aug 2006 Location: France Posts: 46 Thanks: 2 Thanked 6 Times in 5 Posts	DTMF and Symmetric NAT Having recently experienced some voice quality problems with a couple of Providers, I followed the post " How to Improve Your Voice Quality ". I changed my settings as per the post i.e symmetric NAT NO, Optimise Audio YES and indeed call quality did improve. However, I now find DTMF is not being recognised if I make calls to numbers which require " Press 1 for Sales etc ". I have changed back to symmetric NAT Yes and Optimise Audio No and all works perfectly. Why would the NAT setting block DTMF ? Any help gratefully received. Best regards Grahame

02-06-2008, 02:28 AM	#4
ctylor Join Date: Apr 2006 Location: Vancouver, BC Posts: 296 Thanks: 94 Thanked 53 Times in 27 Posts	yeah, try changing those DTMF settings to one of the other two when you have the audio optimized; it might work better Update: I imagine it could be anything. It would take a network engineer and a fat wallet to ever truly get to the bottom of various bugs in the system. Glad to see it was easily resolved. Last edited by ctylor; 02-07-2008 at 01:21 AM.

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02-05-2008, 12:07 PM	#2
green Senior Member Join Date: Jul 2007 Posts: 143 Thanks: 13 Thanked 20 Times in 19 Posts	I suppose this issue is not related to NAT directly. Just try to change DTMF settings (rfc2833 vs SIP INFO) on your side and check the result.

02-05-2008, 07:47 PM	#3
Grahame Member Join Date: Aug 2006 Location: France Posts: 46 Thanks: 2 Thanked 6 Times in 5 Posts	Thanks for the reply. I'm set on my side to RFC 2833 ( default ). The only changes I can make are to PCM or SIP INFO. Did you mean change to SIP INFO ? Grahame

02-06-2008, 10:11 AM	#5
Grahame Member Join Date: Aug 2006 Location: France Posts: 46 Thanks: 2 Thanked 6 Times in 5 Posts	I have reset Symmetric NAT to No and Voice Optimisation to Yes. I have tried DTMF as PCM or SIP INFO on my ATA ( ZyXel P2002L ) and IVR calls work fine using either. Why this should work and RFC 2833 does not I have no idea. Many thanks for your help Best regards Grahame