Remote Maintenance Module - Nortel DMS-100 Series Maintenance Manual

Maintenance overview 1-43
Primary ports that map one to one with DS-1 links are known as equipped
ports. The number of equipped ports in an LCA depends on the number of
DS-1 interface cards provisioned in the HIE. If three DS-1 cards are
provisioned, all three primary ports (0, 1, 2) for each LCA are equipped. If a
port is unequipped, its ports are either not used or are used for features
contained in additional RLCM-EDC feature packages, if provisioned.
Note: Links 0 and 1 are message supporting links that have special
maintenance protection applied to them. On each DS-1 message supporting
link, a channel 12 looparound connects the outgoing side of channel 12 to
the incoming side of channel 12. This looparound is called extended DS-1
maintenance. The looparound prevents manually busying the link where the
looparound is applied when the unit it supports is still in service. When the
unit this link supports is manually busied, the looparound (extended DS-1
maintenance) is disabled. At this time, the link can be busied and the
looparound is re-enabled as NT6X50 card diagnostics for maintenance of the
DS-1 link.
Figure "RLCM-EDC link, port and channel structure" shows RLCM-EDC
link, port, and channel structure.

Remote maintenance module

This section describes the remote maintenance module (RMM) in an
RLCM-EDC.
RMM description
The RMM, which occupies shelf position 47 in the RLCC cabinet, is a
modified, cost-reduced form of the maintenance trunk module (MTM). The
RMM contains its own processor, which performs scanning of the service
circuits and digit collection during ESA.
The RMM C-side interface uses a pair of DS30A links, one to each LCC in
the HIE shelf. The DS30A links ensure the RMM is operable, regardless of
which LCC is active. The LCC passes maintenance requests from the host
to the RMM and provides a link between the RMM and line circuits in the
LCA. At the host office, RLCM-EDC maintenance is directed to the RMM
using the MAP terminal. The following figure shows how the RMM
communicates with both the host and the LCA through the LCC.
DMS-100 Family Maintenance Manual ABSK007