Solved Codec Question

[gigaboy]

I use a couple of SIP trunks from Twilio. The codec they support is G711 mu-law. I have this inserted into the 3cx / SIP Trunks / Options / Codec Priority section.

However, I've noticed that if I look at extension codecs Extension / Phone Provisioning / Codec, that there are 4 defaults (PCMU/PCMA/G722/G729), but not the G711-mu-law. Does this impact performance? Should the defaults be removed and only use the G711..?

 

[leejor]

PCMU = G711u PCMA= G711a, just different terminology.
The sets usually have a preferred Codec, and a order in which to use the others. The one at the top of the list will be first choice if both ends agree. If one end is set to only use G711u, and it is in the list at the other then, then that will be used.

 

[gigaboy]

Thanks for the clarification!

 

[eddv123]

Additional FYI. G.711 u-law is normally used in the U.S and Japan where a-law is used in most other countries.

 

[YiannisH_3CX]

For better performance i would recommend settings the same priority of codecs to both the trunk and the extensions.