Alcatel 4400 via PRI

This page explains how to connect Asterisk to an Alcatel PCX 4400 via a 30 channel ISDN E1 trunk. It might not be the only way or the best way of doing it as I have been figuring this out as I go along but could be a useful guide. Please update or comment if you know a better way of doing a particular thing.

This guide assumes you have already setup an Asterisk server and have an Alcatel 4400 connected to the PSTN.

Resources and current progress

A more upto date version of this document was at the forum here:


You'll need the following:


  • A PRA2 isdn card for the PCX 4400
  • A T1/E1 card for Asterisk, I've used a Sangoma a102u, an equivalent Digium card would do too
  • a cable to connect the two - I used a TY2 96PT at the Alcatel end which I patched into the back of a UTP socket and then used a normal UTP cable to connect to the Asterisk box. The connections are like so

Alcatel Asterisk
1 blue txb (tip) 1
1 red txa (ring) 2
2 blue rxb (tip) 4
2 red rxa (ring) 5

Asterisk Configuration





trunkgroup => 1,16
spanmap => 1,1,1


channel => 1-15,17-31 


; this needs improving as it only allows fixed length of extension numbers at present
exten => _[0-24-8]XX,n,Dial(zap/g1/${EXTEN})  ; internal calls
exten => _9XXXXXXXXXXX,1,Dial(ZAP/g1/${EXTEN}) ; 9 for external calls

Alcatel Configuration

1. Install the PRA2 card

  • Under Shelf/Board create a PRA2 object at the appropriate address
  • Plug the board in

2. Create a trunk group for Alcatel<->Asterisk

  • Under Trunk Groups, name it something like Asterisk
  • Q931 signal variant=ISDN all countries
  • Under Trunk Group:
    • B channel choice=yes
    • Under Access create an object:
    • If your card is in shelf 0, slot 4 the physical address will be 0-4-0
    • access type=T2

3. Set the physical link parameters

  • Under Shelf/Board/PRA2/Digital Access set
    • Network mode=yes
    • CRC4=yes

4. Set a route for calls from Alcatel->Asterisk

My Asterisk extensions begin with 3, so under Translator/Prefix plan

  • 3 - Open routing no.
  • Node number=the ID number of the Asterisk trunk group

5. Enable trunk to trunk dialling

This enables Asterisk->Alcatel->PSTN (thanks again Frank :)

  • Under Classes of Service/Connection COS/5 set Rights COS 5 to 1

Different Connection Types?

I have also tried setting both ends to QSIG instead of isdn all countries/euroisdn but haven't had any luck with this.

Created by: mdawson, Last modification: Wed 16 of May, 2012 (18:47 UTC) by admin
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