Lucent Technologies DDM-2000 OC-3, User & Service Manual

Page: 2075 / 2536

DLP-503
: Detailed Level Procedure 363-206-285
Page 3 of 10 Issue 2, February 2000
DDM-2000 OC-3 M
ULTIPLEXER
Table B – BBF2B/BBF2C TGS/BBF4 TG3 Synchronization Provisioning Topologies
NE 1 NE 2 Application Comments
Free Running Line Timing - Sync Out This topology, although not recommended, results in
having a SONET subnetwork operating asynchronously
with respect to other NE’s in the network. The NE’s
deriving timing off the NE provisioned for Free Running
will be synchronized to it but not to the rest of the
network. The DS1 timing output is normally used to
synchronize other NE’s to a PRS. In this topology the
timing of the Free Running NE is being distributed by the
use of the DS1 output timing reference in the absence of
Synchronization Messaging. In the presence of
Synchronization Messaging, the DS1 output will carry
DS1 AIS. If automatic synchronization reconfiguration is
supported and enabled in a system, the NE 2 system will
attempt to switch to a better quality line timing source, if
available.
Free Running External - Mult This timing topology is not supported. The two network
elements will be operating asynchronously from each
other.
Free Running External - Sync Out This timing topology is not supported. The two network
elements will be operating asynchronously from each
other.
External - Mult Line Timing This topology is used when one of the NE’s does not
have access to an external synchronous reference and
needs to be synchronized to an NE whose timing is
traceable to a PRS. The NE provisioned for Line Timing
will derive its timing from the NE provisioned for External
- Mult timing thus operating synchronously with that
respective NE. The NE provisioned for External - Mult
timing could use its DS1 output to distribute its incoming
DS1 timing reference to other shelves in the bay to
conserve ports on the BITS.
External - Mult Line Timing - Sync Out This topology is used when one of the NE’s does not
have access to an external synchronous reference,
needs to be synchronized to an NE whose timing is
traceable to a PRS, and timing is needed to be distributed
where NE 2 is located. The NE provisioned for Line
Timing - Sync Out will derive its timing from the NE
provisioned for External - Mult timing thus operating
synchronously with that respective NE. Its DS1 output
could serve as a reference to distribute timing to a BITS
in that CO. The NE provisioned for External - Mult timing
could use its DS1 output to distribute its incoming DS1
timing reference to other shelves in the bay to conserve
ports on the BITS.