[Freeswitch-users] 2 B Channel Transfer (2BCT) and FreeSWITCH

Krzysztof Drewicz krzysztofdrewicz at gmail.com
Fri May 7 11:19:59 PDT 2010

2010/5/7 Brian West <brian at freeswitch.org>:
> I don't know of any stack or endpoint using either libpri or sangoma's stack that can do a TBCT

Looks like * does do this job:

Status: Functional in DMS100 in Asterisk 1.4, and beta patch for 5ESS,
NI2 2BCT added into libpri trunk by mattf 2007-09-21
Contributors: mflorell (mflorell at-the-domain gmail.com)


; For digital ports using ISDN PRI protocols:
;   Support switch-side transfer (called 2BCT, RLT or other names)
;   This setting must be enabled on both ports involved, and the
;   'facilityenable' setting must also be enabled to allow sending
;   the transfer to the ISDN switch, since it sent in a FACILITY
;   message.

But, this was coded in USA and for 5ESS, for europe i couldn't use it
with EuroISDN.
By the way, some guy (from Germany) did it for PRI connected between
enterprise PBX-grade Alcatel PBX (not Carrier grade) and asterisk like
2-3 years ago, only with chan_capi and AFAIR dialogic cards, as for
openzap/dahdi i havn't seen working solution by myself.

maybe commercial PRI stack from Sangoma is a good way to start?

also are you sure that 2BCT is required? maybe the 'path replacment'
or some QSIG variant singalling will be more appropriate?

>From my knowledge: some not-so-common ISDN features are realized by
different vendors in some VERY different ways (try to QSIG-GF Siemens
with Avaya or even Alcatel with Lucent...) so the question is 'is the
other side supporting this as well, and if it's compatible with my
isdn PRI stack'

wish you many luck on this, as i haven't found good and reliable
solution for this (vendor independent and 'other side'-independent).
I've been lurking for this functionality for years now.


More information about the FreeSWITCH-users mailing list