Rmm Maintenance - Nortel DMS-100 Series Maintenance Manual

1-60 Maintenance overview
takeover. In the takeover state, the InSv unit assumes control of the lines
associated with the OOS mate unit, in addition to its own. Also, the InSv
unit has access to the DS30A C-side ports formerly used by the OOS mate.
All 20 line subgroups are accessed by the DCC of the InSv unit.
Takeover also occurs when one LCA control complex, the LCM processor
and digroup card fails, the remaining control complex can support all DS-1
links and the LSGs of both LCAs.
Calls in process at the time of takeover are terminated and must be redialed,
but calls already connected and in progress are maintained.
LCC takeover
The LCC provides an interface between the LCA and the DS-1 interface
cards in the HIE shelf. Each LCA is associated with an LCC in the HIE
shelf. If an LCA shelf fails, it is considered inactive and takes down the
associated LCC.
Likewise, if an LCC fails, it takes down the associated LCA shelf. If either
an LCC or an LCA shelf fails, the active LCC and LCA perform a takeover
and support the DS-1 links of the inactive LCC and LCA. Takeover is
possible because of duplicated paths between the LCA shelves. A takeback
occurs when the inactive LCC and LCA become active again.
Takeback
When the failed unit is returned to service, the subscriber lines in takeover
are redistributed back to their normal processor. No calls in the talking state
are lost when returning to the normal mode of operation.

RMM maintenance

The RMM performs the following maintenance functions:
297-8381-550 Standard 02.02 April 1999
bootstrap-level (direct monitor) functions
RMM table control and MAP workstation maintenance
scan monitoring processes
interface with line test equipment
self testing