Can someone explain this to me?

Hello!

I have been posting quite a bit lately, so please bare with me, I’m still learning how all of this works! :smiley: Anyway, I was reading a tutorial on how to dial through a SIP trunk and I saw that the syntax for the Dial application when dialing through a SIP provider is: Dial(SIP/provider/5555555). I see how to use the syntax, however I was wondering if someone could explain to me how it works? By this I mean is it sending the call to the gateway and changing the caller ID to be the “5555555” in this example? If not, how does the gateway know the number you dialed? Please tell me if you need me to try and clarify for you…it is a little hard to explain.

Thanks!

Hi hope this helps:

…technology…Peer…number to dial
…|…|…|
…|…|…|
Dial(SIP / provider / 5555555)

The peer called provider is the name of your “SIP Trunk” so in the dial command you are telling to asterisk to use that peer, then the 5555555 is the number that the peer(called provider) will receive in order to dial.

You need to add in the sip.conf the settings for that peer called provider in order to use it.

Caller ID relates to the opposite direction.

The number is used as the user part of the SIP URI in the method line of the SIP packet. It is also used as the default value for the user part of the URI in the To: line.

For more details see RFC 3261. You can also use the sip set debug on command to see exactly what is sent.