Recommended Jitter Buffer Configuration for Asterisk 11.25.3 to Address Call Quality Issues

[shubonnsei]

Hello Asterisk Community,

We are using Asterisk version 11.25.3 in our CTI system, and we’re experiencing call quality issues We are currently experiencing issues with call quality, specifically intermittent audio and poor sound quality, on our CTI system running Asterisk version 11.25.3. To address these issues, we have made some adjustments to our Jitter Buffer configuration, but we would like to seek advice on optimizing the settings further.

Here is our current configuration:

;------------------------------ JITTER BUFFER CONFIGURATION --------------------------
jbenable=yes
jbforce=yes
jbmaxsize=200
jbresyncthreshold=1000
jbimpl=adaptive
jblog=yes

Could you please provide recommendations on the following points?

1. Is the jbmaxsize setting of 200ms sufficient, or should we consider increasing it to 300ms or 400ms for better handling of network jitter?
2. For jbresyncthreshold, would lowering the threshold to 500ms or 250ms improve audio quality, or is it best left at the default of 1000ms?
3. Are there any other adjustments or best practices for Jitter Buffer configuration in Asterisk 11.25.3 that we should consider?

Any advice or suggestions from those with experience dealing with similar issues would be greatly appreciated.

Thank you in advance for your help!

[david551]

Best practice is to disable it and to use a provider whose jitter is within the range that the phones can handle. As such, if you cannot achieve that, any setting has to be empirical.

You should also check on lost packets, as jitter buffers cannot help with those.

The round trip delays with the figures you are suggesting will be problems in their own right.

[ssether-usinternet]

I’d tend to agree with the other commenter. The phones themselves generally have jitter buffers as well. Adding more and larger jitter buffers can only decrease the perceived calling experience.

As you increase the buffer size, there’s larger delays for callers, and people will start talking over one another. Even at 200 ms the lag is noticeable.

I’d look into other issues on your network before increasing jitter buffers. The problem could be anywhere from your local network, to your ISP, to whomever you’re using as a carrier.