Nortel DMS-100 Series Maintenance Manual page 95

The DS30A ports in the LCA are numbered 0-7. A list of the port functions
appears in the following table.
Table 7 LCA port assignments and use
Number Port type
0,1, 2 Primary
3, 4, 5 Image
6 Interlink
7 Maintenance
DS-1 interface cards
Slots 19 and 20 of the HIE shelf contain the DS-1 interface cards (NT6X50).
An additional card can be provisioned in slot 21 in place of the filler panel.
Each DS-1 interface card accepts two DS-1 links from the host office
LGC/LTC. The DS-1 interface card connects a maximum of six links to the
LCC.
Two DS-1 cards are required. This requirement makes sure that the two
primary message channels from the LCM are carried on different cards for
reliability. Add a third DS-1 card when you require six DS-1 links to the host.
This event occurs to handle the traffic load of the OPM.
DS-1 ports are not duplicated, but each processor in the LCA shelves of the
OPM can control all six DS-1 ports.
DMS-100 Family OPM Maintenance Manual ISN07 (TDM)/SN07 (DMS) and up
Functions
Carries three message channels for the LCA shelf.
Message channels are mapped on to channels 1, 2
and 3 of each of the two primary DS-1 links. These
links are to the host office. Other channels that carry
speech are mapped on to channels 4 through 24 of
the primary DS-1 links.
Normally not active, these ports become active
when the mate LCA and LCC are not active and
takeover occurs. Port 3 takes over mate port 0. Port
4 takes over mate port 1. Port 5 takes over mate
port 2 of the mate LCA. The mapping of all channels
on to the DS-1 links continues, and the active LCC
takes control of all DS-1 links.
Provides a DS30A link for connections between
shelves. During call processing, the channels on
this port can allow the following condition. A
subscriber line on one LCA can connect to a
subscriber line in the mate LCA. This connection
leaves DS-1 channels to the host office free.
Provides the LCA access to the RMM through the
LCCs. Through the RMM ports, separate line
circuits can be selected. Through the RMM ports,
metallic test access (MTA) connections can be
made to the tip and ring leads for testing.
Functional overview 2-19