Nortel Networks OPTera Metro 3500 - Manual (Page 279)

Hardware feature descriptions 3-51
Planning and Ordering Guide—Part 1 of 2 NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004
STX-192 circuit pack
(NTN415AA)
STX-192 circuit packs can be equipped in slots 13 and 14. The STX-192
circuit pack is rated for operation in the temperature range of 0
° C to +50 ° C.
STX-192 circuit packs provide monitoring and control for provisioning,
cross-connect management, shelf timing generation, and synchronization
messaging. The internal clock quality is Stratum 3 (ST3). The STX-192 circuit
packs also support DS1 ESF BITS synchronization status messaging.
The STX-192 circuit packs manage synchronization and shelf bandwidth as
separate entities. For example, if there is a synchronization failure on the
STX-192 circuit pack in slot 13, and a bandwidth management functional
block failure on the STX-192 circuit pack in slot 14, the system can still carry
traffic and provide synchronization timing to other network elements.
STX-192 equipment operates in 1+1 redundant mode to provide cross-connect
and clock distribution functions for OPTera Metro 3500. It is always
autoprovisioned and cannot be deleted. Only one of the two STX-192 circuit
packs can be taken out of service at a time.
External timing reference input signals
The OPTera Metro 3500 shelf can receive timing signals from an external
timing source such as a stratum clock or a BITS when the shelf is equipped
with a STX-192 circuit pack. The BITS is connected to the network element
by wire-wrap connectors on the left OAM (LOAM). The timing signals from
an external timing source are called BITSIN-A and BITSIN-B.
Equipping rules
The STX-192 circuit pack is a double-width circuit pack that can be installed
in slot 13 and slot 14 of the OPTera Metro 3500 shelf.
Note: You can not mix STX-192 circuit packs with VTX-series circuit
packs (e.g. VTX-48 and STX-192) during normal operation. A circuit pack
incompatibility alarm will be raised will be raised if this occurs.