[asterisk-users] PRI TBCT - Practical Experience, Anybody?

[Kevin P. Fleming]

Jay R. Ashworth wrote:

> I'll assume you've watched it on a PRI, so I'll defer, but I wouldn't
> expect that myself; I would expect that when you tell the switch to
> transfer it, you go immediately from one B channel to 0.

You should expect that; in fact, that's what the 'TB' in 'TBCT' stands
for... for a time, there are two B-channels involved. TBCT is a method
of taking two existing already connected B-channels and linking them
together into the network, it is not a 'transfer' facility where you
provide a target DN and an existing call is 'transferred' to that
destination. That feature is ELT (Explicit Line Transfer) and may also
be known by other names, or possibly Call Deflection (CD) depending on
whether you do it before the call is answered or after.

In the scenario you outlined, the original caller (party A) calls this
mediator (who answers as party B1). They then place a call (party B2) to
you (party C), which you answer. Once that call is established, they can
TBCT party A and party C, thus dropping the party B1/B2 legs. You will
never see party A's identifying information on the call to you unless
party B decides to provide it to you in some fashion; the network
signaling would never know to provide it to you, since this is not a
call transfer in the RDNIS sense of 'call transfer'.

-- 
Kevin P. Fleming
Director of Software Technologies
Digium, Inc. - "The Genuine Asterisk Experience" (TM)