HOW TO Connect your IP-PBX Elastix to ISDN

What is ISDN ?
from Wikipedia :

Integrated Services for Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network. It was first defined in 1988 in the CCITT red book.^[1] Prior to ISDN, the telephone system was viewed as a way to transport voice, with some special services available for data. The key feature of ISDN is that it integrates speech and data on the same lines, adding features that were not available in the classic telephone system. There are several kinds of access interfaces to ISDN defined as Basic Rate Interface (BRI), Primary Rate Interface (PRI), Narrowband ISDN (N-ISDN), and Broadband ISDN (B-ISDN).

In Indonesia (my country), ISDN was provided by PT Telkom Indonesia. This article is base on my customer who wants connect to ISDN as their upstream.

this is the Topology :

As we know, ISDN is using E1 carrier, So we had to prepare E1 cabling to make physical connection. This is the configuration of E1 cabling :

Assuming the cable connection is OK . Then there are several steps you should do :

1. In System tab --> hardware Detector--> Detect New Hardware
   
   
2.  if the cable not OK or unplug or ISDN is DOWN, these color should be 'pink'. If the cable OK, ISDN is UP you will get 'green' color 
   
3. Please check and make sure : /etc/dahdi/system.conf :  loadzone=us
   defaultzone=us
   span=1,1,0,ccs,hdb3
   echocanceller=wanpipe_hwec - inactive,1-31
   bchan=1-15,17-31
   hardhdlc=16
4. /etc/asterisk/chan_dahdi.conf : [trunkgroups]
   
   [channels]
   context=default
   usecallerid=yes
   hidecallerid=no
   callwaiting=yes
   usecallingpres=yes
   callwaitingcallerid=yes
   threewaycalling=yes
   transfer=yes
   canpark=yes
   cancallforward=yes
   callreturn=yes
   echocancel=yes
   echocancelwhenbridged=yes
   relaxdtmf=yes
   rxgain=0.0
   txgain=0.0
   group=0
   callgroup=0
   pickupgroup=0
   immediate=no
   
   ;Sangoma A102 port 1 [slot:0 bus:5 span:1] <wanpipe1>
   switchtype=euroisdn
   context=from-pstn
   group=0
   echocancel=yes
   faxdetect=incoming
   signalling=pri_cpe
   channel =>1-15,17-31
5. For check status in Asterisk console, use command asterisk -rx "dahdi show channels"