Use TCL to solve SIP Trunk call transfer issue

Hi, i have a big issue whit a call transfer over sip trunk. When im doing a call from the CME to a phone on the PBX, and transfer that call back to another phone on the cisco, the call is still routed through the PBX as shown in the picture. The problem is that the PBX is supporting only 32 simultanious calls.

From the PBX i could send commands via telnet directly to ciso, so i could start TCL script etc. under a "call transfer"

is it possible to get the cisco to take over all of the call routing and release the trunk with use of TCL?

the biggest issue is when a large number of phones is transferred in to a conference at the same time.

Any help is welcome!

Thanks in advance!

You need to try and see if you can get ev_transfer_request event when you transfer from PBX phone.  Is it SIP refer transfer ?

Please rfer TCL IVR programming guide for more information.
https://developer.cisco.com/site/voice-gateway/documents/api-documents/index.gsp

Thanks,
Raghavendra

No the PBX does not support REFER Transfer. will it still be possible?
Or is it possible to force a phone in to a conference with TCL in some way? that could help out a lot.

i started reading the TCL IVR programming guide. its a little over my head but i will continue to read it for some understanding.

Thanks!

Can you please explain how transfer is done now ?

If possible a SIP trace helps

Looks like PBX is handling the transfer so you have this issue, if you let CME to do that you may not need Tcl ?

HI.

The directory number on the 2 cisco phones is 101 and 102, the number on the PBX phone is 200.

when 101 dial 200 i see normal sip invite. called number is 200 calling number is 101.

when i do the transfer under the call i see SIP invite with 200 as calling number and 102 as called number.

so when the transfer is completet 102 thinks he is talking to 200. same in the display on 102. its only saying 200.

i will try to get a SIP trace later today, but i think the result will be the same.

its no way for the cisco to know that 101 is calling 102.

so if i understood correctly, the SIP REFER TRANSFER includes information about the transferred phone in the header?

Im going to set up a lab with 2 CME with sip trunk between and the same dialing plan.

How would i get this working on the cisco with the SIP REFER TRANSFER + IVR TCL?

if i get it working with CME to CME i could push the vendoer of PBX to include this function. because this is super important function. we need the PBX because it have some certifications for safety etc

Thanks for the help!

As yawming said earlier, if CME doing the transfer then you don't TCL script. Default application should be able to handle.

Thanks,

Raghavendra