Audio/Voice delay in local network

Discussion in '3CX Phone System - General' started by Severin Meyer, Aug 13, 2017.

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  1. Severin Meyer

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    I'm always observing an audio delay at least about 300ms.
    Whenever I make a call, there is a delay. Also when communicating via internal only (LAN no routers or QoS) as also on the echo test *777

    Thought it was related to the Hyper-V environment and/or Linux release of 3CX.
    So I have installed 3CX on a standalone Windows 10, and the problem is the same.

    I have tried to change connection settings on the yealink T46S phone, as also connecting other phones.
    The delay is also present on android client.

    Currently I'm using 15.5.3554.1, have tried to update to 15.5.3849.1 the delay was the same.
    But afterward the firewall check was never ending, and I have to hard reset the VM. So I was reverting to 15.5.3554.1.
     
  2. Brent - Integra

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    I am having same issue.
    I find earlier firmware in Yealink has shorter lag on the echo test calls to *777.
     
  3. complex1

    complex1 Active Member

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    Just a thought...

    1. The wrong codecs are being used. Codecs are programs used to encode voice signals into digital data for transmission over the network. Try a different one.

    2. You're using old hardware. Old hardware with new software or new networks might not work that well and delay and latency are often a result. You should try using a different telephone adapter or a different phone (if you are using an IP phone or any other VoIP-specific hardware). Your switch might also be a culprit.
     
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  4. Severin Meyer

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    I have just tried the following:

    Revert the yealink firmware to T46S-66.81.0.25
    -> Still the same delay

    Configured an old snom 300 phone
    -> No delay noticable at all

    Test delay from yealink to snom
    -> snom receives stream with no delay
    -> yealink receives strem with a delay > 300ms

    Tried android app on different phones and tablets.
    -> Massive delay (~WLAN)

    Tried on 3CX Windows Client via LAN as softphone
    -> Also a delay but seems to be a bit better than the yealink phone
     
  5. leejor

    leejor Well-Known Member

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    You didn't say whether or not you tried using different Codecs, as suggested earlier. Low bit rate Codecs require more processing time and there may be transcoding going on (the logs will show if it is). Stick with G711 a/u on all devices unless there is some compelling reason to use another.
     
  6. Severin Meyer

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    I have tried all possible codecs, but they all have the same delay.
    As the snom 300 is using the same codecs as the yealink, I don't think the codec is much relevant in this scenario.
     
  7. Severin Meyer

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    I have found a viable solution for the yealink phone:
    It seems, that the default template settings for the jitter buffer are invalid in the 3CX-Template are wrong:
    voice.jib.min =0
    voice.jib.max = 300
    voice.jib.normal = 120

    After configuring the settings in the phone to the default one from yealink it is much better.
    (Going less than 60ms seems to enforce a delay of about 300ms)

    Setting -> Voice -> Jitter Buffer
    voice.jib.min = 60
    voice.jib.max = 240
    voice.jib.normal = 120
     
  8. Severin Meyer

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    As I haven't found any settings in the Android or Windows Client, the delay on these apps is still present.
     
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