Nortel Optical Multiservice Edge 6130, Руководство по планированию, Страница: 67 / 292

OAM&P description 6-7
Planning Guide NT6Q92MA Rel 1.0 Iss 1 Standard September 2006
The user performs loopbacks on an STM-1/4, 10/100BT Ethernet, Gigabit
Ethernet, E1/DS1 and E3/DS3 ports from the
Maintenance application in the
main menu of the local craft access terminal. A facility and a terminal
loopback cannot be performed on the same interface port at the same time.
For complete procedures, refer to Provisioning and Protection Switching
Procedures , 323-1855-310.
Synchronization management
Synchronization is a network level application that ensures all nodes across a
network can trace back to the same clock source. Within a single node,
synchronization prevents buffer overflow or underflow which avoids bit
errors.
Synchronization provisioning on the OME6130 is nodal based. However
synchronization must be planned at a network level to avoid hierarchy
violations and timing loops that cause excessive jitter and can result in traffic
loss.
A network level synchronization plan must take into consideration the
requirements for synchronization sources to be used for timing generation and
timing distribution. A detailed plan must be available to define how to
provision the synchronization parameters on the OME6130 network element
at each site.
Timing generation
Timing generation is the ability of the OME6130 to extract and use the
synchronization reference from any of the defined synchronization inputs. The
OME6130 generates shelf timing signals based on external, line or internal
(freerun or holdover) references. The OME6130 supports a timing generation
hierarchy for two timing references.
E3/DS3 Yes No Yes Yes
10/100BT Ethernet No No Yes No
Gigabit Ethernet Yes No Yes No
Table 6-2
Loopbacks and AIS alarm conditioning
Port type Facility loopback AIS injection on
facility loopback Terminal
loopback AIS injection on
terminal loopback