SIP Trunk Hookflash on Mitel 3300

[ralph]

To the SIP gurus, I have an app server that is connected to a 3300 via SIP trunks.
Currently to transfer a call to another device it uses a second SIP trunk to send the call back to the PBX tying up SIP trunks to our app server for the duration of the call.

My question is this:  Can the 3300 recognize a hookflash/transfer.   
Hookflash my not be the correct term for SIP but that is how I would do it on an analog line for instance.

Ralph

[sarond]

Should be able to do it.

We have a 3300 interfacing a IVR via SIP trunks, when it transfers the caller back to the 3300 the SIP Trunk is released (so it is a blind transfer)
I'm not sure how it works on the IVR side of things I just know it does.

Bit of googling found this, it may be relevant.

http://tools.ietf.org/html/rfc5589

[LoopyLou]

Not a SIP Guru but is there not redirect messages within SIP to send calls to another location? Anyway know the ESNA voicemail now uses SIP intergration to a 3300 and would expect it does a "hookswitch" when transferring calls from its Auto Attendant.

[ralph]

LoopyLou,
It's been a while but I know that when ESNA switched to SIP trunks they used to transfer an incoming call to a second trunk.
I'll reach out to someone I know to see if that's still the case.

Ralph

[LoopyLou]

Never really checked myself as we no longer use the ESNA. Would be interesting to know.