Nortel Networks OPTera Metro 3500 - Manual (Page 335)

Hardware feature descriptions 3-107
Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
DS1 service module (DSM) shelf
(NTN407MA)
The DS1 service module (DSM) is a peripheral shelf connected to an OPTera
Metro 3500 network element. The DSM connects to the OPTera Metro 3500
network element through the ports on a host OC-3 or OC-3x4 circuit pack. The
DSM is a terminal DS1 multiplexer. The DSM has three I/Os. Each I/O
supports 1 through 28 DS1 facilities.
The DSM has two numbered slots for DSM DS1x84 termination module (TM)
circuit packs. DSM DS1x84 TM circuit packs support 1 through 84 DS1
facilities. The two circuit packs provide 1+1 protection. The DSM can be
equipped with one circuit pack for an unprotected configuration.
Equipping rules
The DSM connects to the OC-3 ports on the OPTera Metro 3500 shelf using
one (unprotected) or two (protected) OC-3 optical interfaces. An OPTera
Metro 3500 shelf supports one through twelve protected or unprotected DSMs.
See
Table 3-3 on page 3-6 for operational temperature ranges.
Note: To have up to twelve protected or unprotected DSM shelves on a
single OPTera Metro 3500 shelf, you must use OC-3x4 circuit packs. If
you use OC-3 circuit packs, your maximum number of protected DSM
shelves is four or eight unprotected.
Multiple IS
Multiple intermediate system (IS) is a function that allows the DSM, and
communication between the DSM shelf and the shelf processor on the host
network element, to remain hidden from the NPx and other network elements
in the network.