Lucent DDM-2000 OC-3 User And Service Manual page 826

DLP-513
: Detailed Level Procedure
Page 6 of 20
BBF2B/BBF2C TGS/BBF4 TG3
11. NOTE:
The timing mode of all nodes should be checked before the system is
placed in service. Improper timing modes may cause the system to act
unpredictably or cause a service interruption (for example, if all nodes are
set to line timed mode).
NOTE:
The BBF2B/BBF2C TGS or BBF4 TG3 timing mode may be provisioned
as Free Running , DS1 External , or Line Timed . In free-running mode, the
BBF2B/BBF2C TGS or BBF4 TG3 gets timing from an oscillator on the
BBF2B/BBF2C TGS or BBF4 TG3. In external timing mode, the
BBF2B/BBF2C TGS or BBF4 TG3 gets timing from an external DS1
reference input.
NOTE:
In line-timed mode, the BBF2B/BBF2C TGS or BBF4 TG3 gets timing
from a reference clock recovered from a received OC-3 line rate signal.
Either the MAIN 1, MAIN 2(P), or FUNCTION UNIT C OLIU can be
selected as the synchronization source using the command
set-sync:src={main,main-1,main-2,fn-c};.
NOTE:
Table E depicts all the possible timing topologies which can be
encountered on adjacent network elements (NE) with some comments or
cautionary notes on their application. When the NE is provisioned for line
timing or with the DS1 output in SYNC OUT mode, the assumption is that
the NE is deriving its timing from the optical interface shared between the
two NE's.
DDM-2000 OC-3 M
Issue 2, February 2000
ULTIPLEXER
363-206-285