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Table of Contents

Introduction

In systems with multiple T1 ISDN trunks, some customers prefer using a non-facility associated signaling (NFAS) configuration in order to gain extra B-channels.

Background

This article provides example configurations for NFAS groups in the board configuration files.

Details

NFAS group information is associated with the trunk on which the primary D-channel is located. A unique number must be assigned to each NFAS group for reference:

...

     y = NFAS member number (starting at 0 without any gaps in numbering)

Example 1

   Group #5, D-channel on trunk 0

...

NetworkInterface.T1E1[0].ISDN.NFAS_Member[0].Board = 0
NetworkInterface.T1E1[0].ISDN.NFAS_Member[0].Trunk = 0
NetworkInterface.T1E1[0].ISDN.NFAS_Member[0].NAI   = 4

NetworkInterface.T1E1[0].ISDN.NFAS_Member[1].Board = 0
NetworkInterface.T1E1[0].ISDN.NFAS_Member[1].Trunk = 1
NetworkInterface.T1E1[0].ISDN.NFAS_Member[1].NAI   = 6

Example 2

   Group #3, D-channel on trunk 2

...

NetworkInterface.T1E1[2].ISDN.NFAS_Member[0].Board = 0
NetworkInterface.T1E1[2].ISDN.NFAS_Member[0].Trunk = 2
NetworkInterface.T1E1[2].ISDN.NFAS_Member[0].NAI   = 4
 
NetworkInterface.T1E1[2].ISDN.NFAS_Member[1].Board = 0
NetworkInterface.T1E1[2].ISDN.NFAS_Member[1].Trunk = 3
NetworkInterface.T1E1[2].ISDN.NFAS_Member[1].NAI   = 6

Product List

All Dialogic CG series digital boards.

Glossary of Acronyms / Terms

 NFAS:  Non-facility associated signaling; a mode in which a single D-channel on a T1 trunk carries the signaling for all B-channels on several T1 trunks. This leaves the 24th channels on the trunks without a D-channel free for use as B-channels. NFAS is not supported on E1 trunks.