Sangoma Transcoding Card Bug – Drops Audio Samples

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Asterisk Users 3 Comments

There is a serious bug in Sangoma transcoding cards. The card has an internal, small jitter buffer and it drops samples from the audio stream when there is high jitter in the network. The bandwidth is cheap now so for me the only reason to use transcoding is where I have low-bandwidth-high-jitter links. Sangoma said they will not fix it and we had to go back to software transconding.

Do you have any experience with using Digium cards in such scenario?

3 thoughts on - Sangoma Transcoding Card Bug – Drops Audio Samples

  • Are you getting errors like this?

    [Nov 22 10:39:36] WARNING[6307][C-000009a1]: codec_sangoma.c:969 sangoma_frameout: [2724][ulawtog729] Got Seq 7400 but expecting 2154 (time since last read = 0ms), dropped 5246 packets

    From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Grzegorz Garlewicz Sent: Friday, November 22, 2013 2:55 AM
    To: asterisk-users@lists.digium.com Subject: [asterisk-users] Sangoma transcoding card bug – drops audio samples

    There is a serious bug in Sangoma transcoding cards. The card has an internal, small jitter buffer and it drops samples from the audio stream when there is high jitter in the network. The bandwidth is cheap now so for me the only reason to use transcoding is where I have low-bandwidth-high-jitter links. Sangoma said they will not fix it and we had to go back to software transconding.

    Do you have any experience with using Digium cards in such scenario?

  • If you are getting like this dropped packets then nothing to worry.. thisis just an cli message…. in my case I face this but there is no voice delay in actual call.

  • No, there are no visible errors. We performed several simulation tests in our lab to debug the problem. Every time there was jitter in the simulated network the card was dropping audio samples and the voice was illegible. I am wondering if anyone tested Digium in such conditions.