[Asterisk-Users] Damn DTMF Beeps on my calls

[Luki]

Hi Chuji,

this reply is a bit late, but I had to try a few things to confirm. I
managed to capture one of those sporadic beeps in a voicemail (which
in my case are not DTMF tones, but just VERY loud squeaks).

I had * record the voicemail as uLAW, G726-32 and GSM (the original
caller used G726-32 to leave the voicemail, so uLAW and GSM were
generated by *). The uLAW and GSM recordings are fine (no beeps), when
played through Sipura or by downloading the files and opening them in
an audio editor. I could not find any suitable software that would
open G726 files (or convert to uncompressed WAVs). The G726-32
recording, however, when played by the Sipura has this terribly loud
squeak/beep. I verified that with the newest firmware Spa-1000, 2000
and 3000 do the same (which is not surprising since it's essentially
the same engine). A Grandstream 286 plays the same G726-32 recording
just fine -- no beep, no artifacts.

I used G726-32 exclusively to talk to all four ATAs. The original
caller that left the voicemail used a Grandstream 486; however, I
experience the same loud squeaks on conversations between any of the
three Sipura's. Note that if I changed to uLAW, this problem vanished
in my case (I used uLAW exclusively for a few months and never has
this problem).

I guess it's time to contact Sipura about it (I doubt they will be
terribly helpful, though) since this squeaking makes my ear fall off,
and it's sporadic so you never know when to expect it.

If anyone has some ideas or feedback regarding this issue, please post :-).

--Luki