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

[Matt Florell]

On 8/15/08, Don Kelly <dk at donkelly.biz> wrote:
> 1. The carrier you are connected to must be licensed for it and have the
>  necessary software, if the carrier requires, your circuit(s) must be
>  provisioned for it. The originating/destination carriers shouldn't matter.

Most carrier sales people don't know what TBCT is unfortunately, and
even if a carrier is capable of doing it, it is a possiblity that not
all of their equipment is capable of doing it. One client of mine
tried to get TBCT working across all 16 of their PRIs(all on the same
carrier) and it only worked on 4 of them, supposedly because not all
of the telco equipment was capable of the feature.

>  2. Both incoming and outgoing calls can be transferred to a second outgoing
>  call; I think it's theoretically possible to connect two incoming calls, but
>  I haven't done that.

This actually depends on the kind of PRI service you have. For
instance with DMS100 circuits you can only do TBCT with calls that
come in to your circuit, not with outgoing calls.

As for connecting two incoming calls, since that is not possible in
Asterisk(to natively bridge two incoming calls together) I can't see
how you would get that to work even if it is possible in TBCT.

I believe that only DMS100, NI2 and 5ESS PRI signalling protocals are
capable of TBCT with the current zaptel code-base. Also, the two B
channels involved in the TBCT have to use the same D channel.


MATT---