[asterisk-users] SIP REFER

[kalle.odenthal at genion.de]

Hello,
I already wrote a message but maybe the problem I described was pretty unclear, so here a new Try. The thing is it is really urgent and I am not capable to resolve it for myself. Actually I am not a Asterisk Specialist, but I have to use an Asterisk Server for my thesis...
So here the problem in a way breaked down to core-problem:

SIP-Phone1 registered in Asterisk context: [default]
SIP-Phone2 registered in SIPServerX

First
SIP-Phone1 <---Call---> SIP-Phone2

than:
SIP-Phone1  --REFER, with Refer-To:kalle at sipY.com--> Asterisk

Now how could I find the "REFER" in the Dialplan!?

That I can do:

[default]
exten-> ??????,1,do_something(..)

and the "do_something", could be anything, or should it be "Dial" or "Transfer"?

and what might be the ??????

Thank you very much,

Kalle