Asterisk vs ISDN

Some information on how to conect Asterisk to the ISDN 		Chapter 3-2:

NT-mode support

Last update:
2020-03-29
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Choosing which way to go - The NT-mode choice

Most of you are probably still left with multiple options to choose from.
Now the next Question is: Do you only need TE-mode or are you also interested in using BRIs in NT-mode?
Maybe in order to make use of that old ISDN telephone or to connect an POTS phone or an analogue fax via some terminal adaptor or maybe even to connect your old PBX to Asterisk?
Unless you only want to connect a PBX this setup usually involves operating the NT interface in ptmp mode.

First your hardware needs to support NT-mode.
As far as I know all PRI hardware support both TE- and NT-mode which is also supported by all driver options, except CAPI, where it depends on the specific CAPI in use.
For BRI hardware the situation is different, but at least all cards based on HFC chips will support both modes, including the USB dongles.
For other hardware see its manual or probably better search the web.

NT-mode support

capiDepending on the CAPI used
dahdi / zaphfcSupports NT-ptp-mode, NT-ptmp-mode requires a recent version of libpri
(introduced in 1.4.11, better use 1.4.12+) and Asterisk 1.8
Only multiport BRI cards with 5 jumpers per port are natively supported,
ones with only 4 jumpers/port need qozap or a patch for the wcb4xxp module - See Issue #17694
Single-port HFC-S cards need zaphfc or dahdi-hfcs
misdn1Fully supports NT-mode
misdn2 + LCRFully support NT-mode
SirrixFully supports NT-mode
visdnFully supports NT-mode
 

 

 
<-- Chapter 3-1
Hardware and protocol support 		^
index 		Chapter 3-3 -->
Supported features