Nortel Networks NN43001-563 - Manual (Page 61)

ISDN Signaling Link 61
is upgraded to ITG Trunk 2.xx Release 23, upgrade again to the latest
software release. The interim upgrade step is only required if fax support is
needed during the upgrade process.
When the Media Card 32-port trunk cards are upgraded to or installed
with IP Trunk 3.01 (and later), fax calls do not work to nodes running ITG
Trunk 2.xx Release 19 or earlier. This limitation is due to the same protocol
incompatibility that exists between ITG Trunk 2.1 and ITG Trunk 2.xx and
earlier.
Fax Tone Detection Configuration
For IP Trunk 3.01 (and later) fax operation, the V.21 Tone detection check
box must be selected in TM 3.1 in the Configuration window, under the DSP
profile tab. For more information, see
"Configure DSP profiles for the IP
Trunk 3.01 (and later) node" (page 242) .
ISDN Signaling Link
ISDN Signaling Link (ISL) provides the capability of replacing conventional
analog trunk signaling with out-of-band ISDN D-channel signaling.
The ISL interface makes available the flexibility of using ISDN signaling to
analog facilities. When no Primary Rate Interface (PRI) exists between
two Meridian 1/CS 1000M systems, ISL operates in dedicated mode.
A dedicated point-to-point signaling link is established between the two
systems. The signaling information for the selected analog trunks is
transported over the ISDN signaling link. The analog ISL TIE trunks are for
user voice transport. If the D-channel link is down, call control returns to
normal in-band analog trunk signaling.
The ITG is similar to the existing ISL configuration where there is a Virtual
Private Network (VPN) between Meridian 1/CS 1000M systems. Instead of a
one-to-one connection, multiple switches can be networked through a single
ISL interface at each site.
Figure 17 "ITG configuration" (page 62) shows an
IP Trunk 3.01 (and later) trunk configuration with three Meridian 1/CS 1000M
systems. The IP Trunk 3.01 (and later) trunk simulates an analog facility.
The ISL interface is connected to a DCHIP PC Card which provides ISDN to
VoIP tandeming. All IP Trunk 3.01 (and later) IP trunk cards (DCHIP, Leader,
and Follower) are connected through the ELAN subnet. The IP trunk cards
communicate with remote switches through the IP network.
Nortel Communication Server 1000
IP Trunk Fundamentals
NN43001-563 01.01 Standard
Release 5.0 30 May 2007
Copyright © 2007, Nortel Networks
.