Codecs: Opus vs PCMU vs GSM

[Frank86]

We have the latest 3CX Enterprise running on a quad-core VM with Yealink T48S, and T58A phones.

Under PBX settings, I see the OPUS codec at the bottom for both local/internal calls and for external calls.

The default highest priority for internal calls is PCMU; for external calls it's GSM.

Is it a good idea to put OPUS as the highest priority for both internal and external?

If so, do I also have to set it as the highest priority for each extension? Right now, it's the lowest priority under each extension's phone settings for the Yealinks.

 

[cobaltit]

It's a good idea to put whatever codec you want to prioritize as the highest priority. No one can make that decision but you. And yes you have to adjust it on each existing extension because 3CX is not going to automatically change all your existing extensions.

 

[roland_3CX]

We have the latest 3CX Enterprise running on a quad-core VM with Yealink T48S, and T58A phones.

Under PBX settings, I see the OPUS codec at the bottom for both local/internal calls and for external calls.

The default highest priority for internal calls is PCMU; for external calls it's GSM.

Is it a good idea to put OPUS as the highest priority for both internal and external?

If so, do I also have to set it as the highest priority for each extension? Right now, it's the lowest priority under each extension's phone settings for the Yealinks.

Hi Frank,
Some things to consider as you make your decision. For external calls, it's ideal to use a low bandwidth codec (i.e GSM or G729) unless you have a lot bandwidth. Also, keep in mind that Opus does utilize more than enough CPU. For internal calls you can afford to use a high quality codecs since bandwidth is not an issue on the LAN.

 

[Frank86]

Thank you, Roland. Couple of questions:

• Why doesn't OPUS show up as an option for my Yealink T48S phones under Extension > Phone Provisioning? It does for my T58a phones.
• For external calls, does G729 provide better audio quality than GSM?

 

[Frank86]

So, I did play with the codecs and reverted back to the default 3CX ones since both internal and external users complained of choppy voice quality when priority was given to Opus (internal calls) and G.722 (external calls).