Hello,
thank you for reply.
On Thu, Jan 31, 2008 at 12:13:38AM +0100, Iñaki Baz Castillo wrote:
El Miércoles, 30 de Enero de 2008, Jan ONDREJ (SAL) escribió:
On Wed, Jan 30, 2008 at 04:26:26PM -0500, Alex Balashov wrote:
Error: Have you investigated how REFER works? Two examples:
Yes. I know this theory.
case 1)
3 phones (A, B, C)
A calls B and they speak.
B wants to transfer the call to C. So B sends a REFER to A like this: REFER sip:A@IP_A Refer-To: sip:C@domain
So A will receive that REFER and then A will generate an INVITE to C: INVITE sip:C@domain From: A@domain
So in conclusion: a REFER in fact means: "please, invite this other user".
I am trying call transfer in this situation (case 1). It is not working in my default cofnig (attached to this email, there are just removed authentications to simply my testing). Tryed blind transfer and also managed transfer. One of three phnes still goes to undefined state (for example holding an nonexistent call). In different situations different phones.
case 2)
2 phones (A, B) and a gateway.
The gateway calls B and they speak.
B wants to transfer to A so it sends a REFER to gateway like this: REFER sip:gateway@IP_gateway Refer-To: sip:A@domain
So now the **gateway** should generate an INVITE to A. Unfortunatelly AFAIK
most of gateways won't allow it (and it sems logical to me).
What you need is a B2BUA between the gateway and phones. In this way the UAS receiving the REFER will be the B2BUA (that you control) and not the gateway.
This is what I will need in future, but I am now experimenting only with "case 1". I can't experiment on my active openser, so I configured another openser and trying something simple (case 1). But it is not working. :(
An example configuration with call transfer support can be useful for other users too, so it can be good to include it into openser distribution's example configurations.
No, OpenSer is a SIP proxy, not a PBX or B2BUA, it just should route the REFER according to RFC 3261 for in-dialog messages.
Hmm, theory. Does not work for me. After trying to change to asterisk it works with my phones, but I am unable to do this with openser. I don't like asterisk, so I want to configure openser for this situation.
OpenSER is a proxy, so it shouldn't really be "handling" referrals, just passing them back to the user agent/server (UAC/UAS) that will ultimately be taking care of that.
It's not done by default config?
Yes, it's done. The problem you have is that you are sending the REFER to a gateway.
Hmm, really? :(
SAL