CODEC general questions

Asterisk Asterisk Support
1

Hi,

I would have some questions on Codecs…
I am using Asterisk 1.4…
If I understood correctly…

  • Let’s suppose that a provider using some codecs. I need to make sure that my config in SIP.conf will match all these codecs ?
    -… and that My SIP phone will list the specific codec !?

  • Now, If I use a list of codecs, how can make sure that I will use in a specific order ?

  • Typically, I have a landline phone number associated to a VOIP provider.
    I call my “Landline”… call another provider to make an international phone call… I could hear the person, but nobody could listen to me…
    I suppose that this is codec problem ?

  • How could I force a specific codec with Asterisk? (and to declare it ?)

  • if I have :

  • disallow=all
  • allow=ulaw
  • allow=g711

=> Does it mean that I’ll force to use ulaw AND THEN if needed, g711 ?

  • Do you think that GSM codec could work with any provider ?

  • I’ve seen that there are some codec “translation” in Asterisk…
    Could it be the possibility to translate a codec -> another one IF the codec is not supported ?
    -> if so, how to configure this ?? Is that automatic ?

Thanks for your help

Stephane

2

Not all of them, one is enough :smile:

No, you can use a different codec between your sip phone and asterisk than between asterisk and your provider.

[quote=“stephane”]- Typically, I have a landline phone number associated to a VOIP provider.
I call my “Landline”… call another provider to make an international phone call… I could hear the person, but nobody could listen to me…
I suppose that this is codec problem ?[/quote]

You should look your logs, but i do not think it’s a codec problem, is your Asterisk directly connected to Internet with a public IP or did you use a NAT router with a private range of IP’s ? This is probably the first cause of the problem you describe…