Configuring Isdn Nfas - AudioCodes Mediant 2000 User Manual

SIP User's Manual
6. From the 'Clock Master' drop-down list, set the Clock Master to one of the following
values:
•
Clock Master OFF: the Clock Source is recovered from the Trunk line.
•
Clock Master ON: the Clock Source is provided by the internal TDM bus clock
source, according to the parameter TDM Bus Clock Source.
7. Select the other tabs to continue configuring the PSTN trunks.
Notes:
5.4.2

Configuring ISDN NFAS

This section describes how to configure ISDN-NFAS trunks as an initial configuration.
In regular T1 ISDN trunks, a single 64 kbps channel carries signaling for the other 23 B-
channels of that particular T1 trunk. This channel is called the D-channel and usually
resides on timeslot #24. The ISDN Non-Facility Associated Signaling (NFAS) feature
enables the use of a single D-channel to control multiple PRI interfaces.
With NFAS it is possible to define a group of T1 trunks, called an NFAS group, in which a
single D-channel carries ISDN signaling messages for the entire group. The NFAS group's
B-channels are used to carry traffic such as voice or data. The NFAS mechanism also
enables definition of a backup D-channel on a different T1 trunk, to be used if the primary
D-channel fails.
The NFAS group can comprise up to 10 T1 trunks. Each T1 trunk is called an 'NFAS
member'. The T1 trunk whose D-channel is used for signaling is called the 'Primary NFAS
Trunk'. The T1 trunk whose D-channel is used for backup signaling is called the 'Backup
NFAS Trunk'. The primary and backup trunks each carry 23 B-channels while all other
NFAS trunks each carry 24 B channels.
ISDN-NFAS Trunks can be configured offline or on-the-fly.

To configure ISDN-NFAS Trunks offline:
1. In the MG Tree, select the required device; the device's graphical display is displayed
in the Status pane.
2. Double-click the Trunk module
3. In the DS1 Carriers List table, double-click a Trunk; the Trunk SIP Provisioning screen
is displayed with the
Version 5.8
•
When changing 'Protocol Type' from 'None' to any other protocol, reset
the device. You're not required to reset the device when making
subsequent changes to 'Protocol Type'.
•
Most Trunk provisioning parameters require that a Trunk Lock / Unlock
be performed before / after configuring them. When performing a Lock
action, all active calls are dropped and users cannot make new calls. This
is Trunk Out Of Service mode.
•
Upon initial configuration, do not change the Admin State of the trunks to
unlock (it is changed automatically after the device is reset in EMS).
; the DS1 Carriers List table appears.
General Settings tab selected.
5. Element Management System (EMS)
209 October 2009