[Asterisk-Dev] REFER / NOTIFY methods according to RFC-3515

[Olle E Johansson]

Lea wrote:
> Olle,
> 
> Thank you very much for replying !
> 
> The info that the transfer() application works differently from 
> the Dial( ,t) application is not anywhere in the documentation.
> Please consider adding it for the poor unaware users.
> 
> Anyway, I tried to transfer an incoming SIP call (
> after it has been answered) using the following dialplan:
> exten => 5,1,Transfer(SIP/18005551212 at sphone.vopr.vonage.net)
> using the same channel as for the incoming call.
> 
> ...and the Asterisk SIP debug output showed a REFER request 
> being generated (see its listing below).  Great !
> 
> Unfortunately this REFER request was not accepted by the Vonage 
> server and later Asterisk retransmitted it several times after 
> which Asterisk gave up. Thus the TRANSFER FAILED :(
> 
Yes, the transfer() function sends a REFER, then totally ignores what is 
happening with the transfer. It does need a total rewrite for all VoIP 
channels and should propably be considered a bad hack.

For SIP, I've been trying to improve it but it hasn't been on top of my 
priority list since no customer asked for it and not many people use it. 
  Changing it to return failure and wait for failures will propably need 
changing the core transfer() function as well, which will lead to 
changes in other channels...





/O