QUESTION DTMF digits not working when phone is connected to a 2nd router

[redstonemason]

I have 2 ISP's. Let call them A and B. And I have 1 router for each ISP access. Lets call them 1 and 2 The two routers are connected together for convenience internally in the LAN with a backbone ethernet cable.

Router1 is connected to ISP A. Behind that router I have 5 PBIAF instances each running on a dedicated 1:1 NAT'd public IP. My customers use the PBIAF instances remotely. That way I don't have to deploy PBX hardware at their business locations. To them it is a cloud PBX.

My own Yealink Phone connected is directly to Router1 (colocated) and works well. No issues with DTMF.

My outside Yealink phones that are on a whitelist connect to their respective PBX's and DTMF works well.

But if I move my own Yealink phone and connect it to Router2 then DTMF digits are not recognized when I make a call to a third party. The digits are recognized locally by the asterisk but they don't get passed to the far end if I encounter a third party IVR.

Question: Why are the DTMF digits landing on the floor. It almost seems that Router2 is the culprit.

I am using licensed g729 codecs on the PBIAF instances. And I am using rfc2833 in the phones, on the PBX's and the VOIP provider.

This is a real head scratcher.

One other noteu. If I disconnect Router1 from Router2 by pulling the backbone ethernet cable out then the DTMF problem goes away. My phone on Router2 works just like any other customer phone should!

Here is a really crude diagram done in MyVisio

 

[TS-79]

Asterisk does not play DTFM tones if it thinks you are entering a feature code. Have you tried turning off feature codes starting with # for example and then seeing if you can enter # on a foreign IVR? You also might try the dial options in advanced settings to temporarily not allow transfers and see if that fixes the problem. At least you can try isolate if the PBX is silencing them or not.

 

[redstonemason]

Thanks for your help. But the IVR's that we are calling don't even need the # sign entered. They are typically menus that need a single digit such as press 1 for customer service, 2 for technical support, 3 for billing and so forth...

 

[TS-79]

Have you tried to call yourself and see if you hear any tones? This may give you some more clues if you play around with trying different digits etc.

 

[redstonemason]

Kudos to you folks. The DTMF sounds were not audible. I think the firewall is not accepting the full range of RTP ports because in some cases I could not hear either DTMF or voice. In other words, one way audio.

I think know how to fix it. The goal being a zero internet footprint and whitelists only !

Thanks.