Nortel DMS-100 Series Maintenance Manual page 38

1-22 Maintenance overview
The DS30A ports in the LCA have numbers 0 to 7. The following table lists
DS30A port functions.
LCA port assignments and use
Number
0, 1, 2
3, 4, 5
6
7
The LCC provides system clocks for the DCC, RMM, and LCM. When
both units of the LCM are active, LCC-0 is frequency-locked to the primary
DS-1 link of the LCC-0. The LCC-1 clock is locked to LCC-0. Both LCC
clocks get timing from the host LTC.
297-8211-550 Standard 05.01 August 1999
Port type Functions
Primary Carries three message channels for the LCA shelf.
Message channels map to channels 1, 2, and 3 of
each of the two primary DS-1 links to the host
office.
Other channels that carry speech map to channels
4 through 24 of the primary DS-1 links.
Image Normally inactive, these ports become active if the
mate LCA and LCC are inactive and takeover
occurs. Port 3 takes over mate port 0 and port 4
takes over mate port 1 of the mate LCA. Port 5
takes over mate port 2 of the mate LCA.
The system maintains mapping of all channels to
the DS-1 links. The active LCC takes control of all
DS-1 links.
Interlink Provides a DS30A link for connections between
shelves.
The following action occurs during call processing.
The channels on this port allow a subscriber line on
one LCA to connect to a subscriber line in the mate
LCA. This action leaves DS-1 channels to the host
office free.
Maintenance Provides the LCA access to the RMM through the
LCCs.
Selection of separate line circuits can occur through
RMM ports. Metallic test access (MTA)
connections can connect to the tip and ring leads
for tests.