363-206-285 Detailed Level Procedure: DLP-513
Issue 2, February 2000 Page 7 of 20
DDM-2000 OC-3 MULTIPLEXER
Table E – BBF2B/BBF2C TGS/BBF4 TG3 Synchronization Provisioning
Topologies
NE 1 NE 2 Application Comments
Free Running Free Running This topology is not supported. Both systems are
operating asynchronously from each other.
Free Running Line Timing This topology is allowed but 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 a PRS
on the network. If automatic synchronization
reconfiguration is supported and enabled in a
system, the NE 2 system will attempt to switch to
another better quality line timing source, if available.
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.
To Next Page
Loading...
Need help?
General
