Hi,

also you should check, what your ITSP really supports. I don't think our Cisco PGW's here at Telefonica Germany supports properly Call-Transfer and it is absolutely ok, since we are providing Class 4 services and not Class 5 services (which would be handled by our Class 5 infrastructure). Call-Transfer ist a typical Class 5 feature which is normally supported by a PBX and not natively by a class 4 infrastructure.

Kind regards, Carsten

2011/2/25 Iñaki Baz Castillo ibc@aliax.net:

2011/2/25 niklas rehnberg niklas.rehnberg@gmail.com:

...

Hi, Have following issue:

Alice calling Bob. Bob make call transfer to Charlie  (works fine) Charlie transfer Alice to David.    (the call break)

Why is not possible to transfer the call more than one time? Is it any parameters?

My ITSP use SER together with Cisco MGW.

Niklas, nothing in SIP protocol neither in SER/Kamailio makes your scenario to fail. It must be a problem in your custom setup. Try identifying the problem capturing SIP traces. Also take into account that a proxy doesn't participate at all in the process of a "call transfer". It's just a transparent mechanism for a proxy.

-- Iñaki Baz Castillo ibc@aliax.net

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SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users

Hi. We have proverb for this, i don't know english version but it goes like this: "When it isn't known what it's all about, it's about money"

Your ITSP had troubles with proper handling second transfer for billing purposes so decided to disable it. Proxy doesnt participate in call transfer, but ITSP it must charge users properly: Alice should pay just for call to Bob, Bob for "his" call to Charlie and so on. If You are using sipX You should use sipXbridge, it replaces REFER with INVITE and bridges calls.

Grzegorz Stanislawski

W dniu 2011-02-25 11:40, niklas rehnberg pisze:

Hi, Thank for the quick response. The issue occur only when the Alice is a PSTN client. My ITSP says that they only supporting one call transfer (very strange). They can not explain why etc... PSTN client: Alice MGW/MGC(ITSP): Cisco/SER Our sip server: SIPX

BR Niklas 2011/2/25 Iñaki Baz Castillo <ibc@aliax.net mailto:ibc@aliax.net>

2011/2/25 niklas rehnberg <niklas.rehnberg@gmail.com
<mailto:niklas.rehnberg@gmail.com>>:
 > Hi,
 > Have following issue:
 >
 > Alice calling Bob.
 > Bob make call transfer to Charlie  (works fine)
 > Charlie transfer Alice to David.    (the call break)
 >
 > Why is not possible to transfer the call more than one time?
 > Is it any parameters?
 >
 > My ITSP use SER together with Cisco MGW.

Niklas, nothing in SIP protocol neither in SER/Kamailio makes your
scenario to fail. It must be a problem in your custom setup. Try
identifying the problem capturing SIP traces.
Also take into account that a proxy doesn't participate at all in the
process of a "call transfer". It's just a transparent mechanism for a
proxy.

--
Iñaki Baz Castillo
<ibc@aliax.net <mailto:ibc@aliax.net>>

---

SIP Express Router (SER) and Kamailio (OpenSER) - sr-users mailing list sr-users@lists.sip-router.org http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-users