Garbled voicemail

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Asterisk Users 2 Comments

Our Asterisk system ( has been very
stable and generally doing a good job — except that one day,
voicemail recordings started being garbled.

It only manifests when the VM comes from our telco gateway
service — OnSIP/Junction — and not from internal phones or
from an Asterisk box I have at home.

We have voicemail set to record to WAV, and real files are
being generated — but it sounds incredibly sped up, faster than
chipmunks. Completely unintelligible, even if you pull it into
an audio editor and slow down playback.

It is not perfectly consistent, but it happens in about 85% of
voicemail recordings left from the outside world through OnSIP.

We’ve had several years of trouble-free voicemail before this.

Anyone seen anything similar? Advice? Wild speculation?


2 thoughts on - Garbled voicemail

  • Hi Dan,

    my wild speculation: It’s some kind of timing/synchronisation problem.
    Do you use jitter buffer an/or echo cancelation?

    Best regards,

  • Hello,

    this is a know problem when you are writing the voicemails over a nfs
    link. you have to start asterisk with the -t option to write voicemail
    records to the local /tmp and copy it to the final destination after it
    is finished.

    as far as i remember the first 10 seconds are ok and then the speed up
    started but with the -t option it was completly solved.

    best regards


    Am 09.02.12 18:16, schrieb Ruben Rögels: