VoIP hardware is developing fast - this is where you ask all those “how do I make my SIP Telephone, Adapter or Asterisk box work with my voip provider?” questions.
User avatar
By Michael
Dear WelshPaul,

My OBI setup seems to work well together thanks to your time and patience. That was until this mystery issue occurred and what a crazy/weird issue this is! :-/

I made a call today from my new OBi1062 using the SP4 to OBiLINE combination and spoken for several minutes to this holiday rep on the PSTN landline. Then, without warning I heard a key tone from my end that wouldn't stop. It was if someone was pressing a number key and no matter what I did, I couldn't stop it. What could this be? :-o

I can use sipgate, Google Voice, etc without any issues. Just this SP4/OBiLINE/PSTN combination. :beaten:

Any ideas?


User avatar
By WelshPaul
This has popped up in the past, nobody has found the cause or a fix. It somehow appears to show it's ugly head when bridging calls! :(

It's hard to diagnose because it doesn't happen all the time if at all for most users. It may be that voice frequencies are triggering DTMF. Talk-Off, or Talkoff, is the term that describes when a human voice is able to trigger touch tones, or DTMF tones during a telephone call. Talk-Off occurs when a signal processing system tries to translate sounds into to touch tones. Some people's voices are able to recreate touch tones frequently relative to the general population.

A similar issue was posted here: viewtopic.php?f=10&t=725&sid=1be9abe6c2 ... d&start=15

Unsure if this is firmware related or a a glitch in the OBiLINE itself, personally I haven't ever encountered the issue. Can you provide any further information such as could the other person hear the tone or was it only heard by you? Has it happened since? Were you on speaker phone (either end) or using the phones handset?

In the meantime, let's try making the following change on your OBi202 and the first OBi1062 device you purchased. Log in to each device and navigate to Service Providers > ITSP Profile D > General and configure the DTMFMethod parameter like so:
  • DTMFMethod: RFC2833
Do the same for ITSP Profile C > General on your OBi202 and the second OBi1062 you purchased recently.

Now we wait! :)
User avatar
By Michael
I will certainly give this a try. :-D

This has happened to me before and it tends to be several minutes into the conversation. Both parties hear the tone and unfortunately the person on the other end thinks i'm mucking around. :-o

Try explaining that to your wife during an arguement :sweat:

Thank you for your patience and time.
User avatar
By WelshPaul
Couldn't help but chuckle when reading your reply! :laugh:

I was going to ask if the other person was female but held off, previous reports have indicated that a female voice was present at the time of these tones. Women have a higher pitch voice than men, talkoff?!?

Hopefully switching to RFC2833 resolves the issue. :)
User avatar
By WelshPaul
Michael wrote: Wed 19th April 2017, 19:38 I gave my mother a call tonight on the shared OBiLINE/PSTN and the issue started as soon as she spoke. I tried it twice and bombed her twice. :-o

Any ideas?
While switching to RFC2833 is the correct parameter for UK users, I didn't think it would resolve the issue. I'm also not convinced this is caused by "talkoff" because it only appears to pop up when bridging calls. When making calls via a telephone connected directly to the OBi202 phone 1 or 2 port it doesn't happen right? Again, neither does it happen when making VoIP calls on the OBi202 or both OBi1062's right?

My advice is to open a support ticket with Obihai. Before you do, try and get a syslog of a call experiencing the DTMF tone issue as it actually happens. Sounds complicated but it really isn't - See here. You basically install a program on your PC and run it, you then need to enable the syslog feature on your OBi1062 and enter the IP address of the PC that's running the syslog program. Provide OBihai with the syslog and explain clearly that your experiencing DTMF tones being played back on calls made via your OBi1062's when bridging calls to your OBi202 and out over the OBiLINE.

Having never experienced the issue myself it's hard to come up with a solution. As calls made via the OBi202 and all VoIP calls work without issue, I suspect the issue may be hardware or firmware related.
User avatar
By WelshPaul
I was wondering if the issue is also present when connecting the OBiLINE to one of the 1062's rather than the OBi202.

Anyway, let us know how you get on with OBIHAI support.
User avatar
By Michael
I have yet to use that diagnostic tool as I have been away. I bought a new OBiLINE thinking this will cure the problem but in fact after 6 minutes and 25 seconds it happened again. Also could hear my voice speaking as an echo. This only occurs when I use the shared option. Works okay through the OBi202.

I will keep you posted.
User avatar
By WelshPaul
Can you not try and connect an OBiLINE directly into one of the USB ports on a OBi1062? Make a call and see if you get the dreaded DTMF issue.

Did you open a support ticket with Obihai?

OK thanks, what VPN are you using ??

A good write up on SIP ALG: https://www.voicehost…

Thanks very much. Really appreciate it! :-D

Attached below is my latest OBIHAI UK configuratio…