[asterisk-users] Which policy for ISDN BRI support in NT/PtMP ?

[Matthew Fredrickson]

Olivier wrote:
> Hi,
> 
> As you may know, these ISDN BRI features are very important here in 
> Europe as ISDN Basic Rate Access is very popular among Small & Medium 
> Entreprises.
> I don't really know why but it seems that in many countries, default is 
> to install small PBX using Point-to-Multipoint (PtMP) mode as opposed to 
> Point-to-Point (PtP) which is the norm for PRI.
> 
> So basically, in several countries, SME are equipped today with PBX 
> connected with TE/PtMP interfaces to telco BRI lines.
> When we address those SME, my opinion is that it's very useful to be 
> able to support any combination of TE/NT, PtP/PtMP modes.
> 
> Latest 1.6 Asterisk and 1.4.8 Libpri introduced a new set of welcomed 
> ISDN BRI features.
> Unfortunately, NT/PtMP is not available at this time, in latest 
> Zaptel/Asterisk/Libpri.
> 
> My question is "what is the policy concerning NT/PtMP ?"
> Is it really hard to extend Libpri to support this mode ?
> Or shall mISDN remain the way to go when NT/PtMP is needed ?

Hey Olivier,

I actually was the one that did a lot the work in adding the BRI support 
to libpri/chan_dahdi.

NT PTMP is very significantly different, in that you have to do much 
more from a TEI management perspective.

Most people's needs that I saw were actually fulfilled in using either 
NT or TE PTP or TE PTMP, since they were interfacing with PBXs or using 
TE-PTMP trunks from the telephone network to provide voice trunks for 
Asterisk.

Right now, I would not preclude the possibility that NT-PTMP support 
might be added, but I could not give you a concrete time at which it 
will be done, since it will probably require some significant internal 
changes in libpri.

To answer your final question, for now, if you need NT-PTMP mode, you 
should use mISDN.

Matthew Fredrickson
Digium, Inc.