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

[Jay R. Ashworth]

On Tue, Aug 19, 2008 at 07:35:03AM -0500, Kevin P. Fleming wrote:
> 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'.

*Aha*.  Got it.

So whether I can, as a recipient, get the CNID of the call originated
by the second party depends on whether they can send it to me.

That is, *that* part is a capability of the second party, and the only
capability the second party's IXC has to provide is bare TBCT.  I
understand better now, Kevin; thank you very much.  I'm in that
conference call in about 20 minutes.  ;-)

Cheers,
-- jra

-- 
Jay R. Ashworth                   Baylink                      jra at baylink.com
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