Lucent Technologies FiberReach DDM-2000 - Line Timing in a Ring Configuration

363-206-305
Transmission and Synchronization
Issue 3 June 2000
5-11
Line Timing/Line Timing Configuration
5
The line timing/line timing configuration (shown in Figure 5-5) provides an
alternate timing arrangement that integrates loop feeder and customer location
networks into the digital synchronization network as required by the SONET
standard. This application is used when a synchronization source is not available
locally to the DDM-2000 host. The network is synchronized to a remote clock via
the SONET connection. The remote clock source should be traceable to a primary
reference source that is Stratum 3 or better. The local DDM-2000 multiplexer
times its transmitted signals at the low- and high-speed interfaces from the
internal oscillator that is locked on the SONET connection. The remote DDM-2000
FiberReach Multiplexer recovers timing from the incoming OC-1 signal and
unidirectional timing path and uses this timing for its transmitted signals.
Figure 5-5. Line Timing in a Ring Configuration
TGS
DDM-2000
OC-3
OLIU
DDM-2000
FiberReach
OLIU
DDM-2000
FiberReach
OLIU
DDM-2000
FiberReach
Line Timed
Line Timed
Line Timed
remote
timing
reference
active timing direction
OLIU