Question about "Bind to Media Server"

[John2007]

the question is simple. What's the difference between a line/extension Bind to Media Server or not? Or in what case should Bind to Media Server and in what case should not?

 

[ilkeryildiz]

Audio transmit directly between phone(extension) & provider if Bind to Media Server are unchecked (disable).

Audio transmit via "3CX Media Server" between phone & provider if Bind to Media Server are checked (enable).

If you will not bound both external extension and VoIP provider to Media Server, they will try direct RTP connection. But they both should support "re-INVITE", otherwise they will be explicitly bound to Media Server

 

[N_G]

Thanks for your post Ilkeryildiz! Exactly right. You would bind to media server if you are experiencing problems or talking via a VOIP provider. Basically it means 3Cx will handle more of the call, i.e rather then leave it up to the end points themselves.

 

[juanky]

Binding to Media Server and Codecs

I think binding to media server limit you what codec can use... Because of 3CX only supports 711 and GSM... With DSL links these codecs are huge in terms of bandwith using...

 

[archie]

juanky, you're right. Binding to Media Server limits to use G.711 or GSM. But GSM has a really good compression rate. 20 ms of audio is compressed to 33 bytes, so you have only 1650 bytes per second to be passed one way. It's not much load.

 

[juanky]

~13 kpbs doesn't look much ... but if you are using wan (DSL, Cable) lines each Kpbs counts...
Also, a very few SIP hardware devices support that codec... while 729 are (almost) always supported... To be honest i thin only sip software phones supports GSM

The speex looks to be a good alternative... but if the hardware devices doesn't support it...

What about a pluggable codec interface?... So if anyone wants to install a 729 codec plugin ...