Connections For The Synchronized Mode; Figure 4-3: Non-Synchronized Mode Connections Diagram - Nortel Media Gateway 3500 Installation, Operation And Maintenance Manual

Installation, Operation, Maintenance Manual
When a group includes trunks with different clock qualities, connect the most accurate
and stable clock trunks to the Media Gateway board's trunk 9 to 16 (trunk 9 is the
highest quality and 16 is the lowest quality.)

Figure 4-3: Non-Synchronized Mode Connections Diagram

SC
1610 Board
Note:
4.5.2

Connections for the Synchronized Mode

In synchronized mode, the Media Gateway 3500 operates in synchronization with the
PSTN equipment attached to the PSTN interfaces. It derives the synchronization timing
from one of the E1 / T1 / J1 trunks and distributes the timing to all other synchronous
interfaces in the system according to Bellcore GR-1244-CORE line-timing scheme.
When working in synchronized mode, the reference trunks for Primary and Secondary
clock master should be chosen from one of the following ranges: (1-8) or (9-16)
To operate the gateway at redundant synchronization regime, take
these 4 steps:
1. Configure two Media Gateway boards, to provide a redundant synchronization clock
to the whole gateway.
2. Divide the highest quality trunks into two redundant clock reference groups.
3. Connect the highest quality trunks to the same trunks group on the clock master
boards.
4. Assign the highest clock priority to the most accurate and stable ports on both clock
master boards. Note that when assigning priorities, 15 is highest priority, 1 is lowest
priority, and 0 means not to use the associated trunk for clock synchronization.
1.
Version 3.0
Gateway Internal Network
Class 5 switch/
Class 5
PSTN Trunks PSTN Trunks
switch/PBX PBX
Connect Highest
starting from port
For more information, refer to the Programmer's User Manual, document #
LTRT-962xx.
1610 Board
Class 5 Class 5 switch/
PSTN Trunks PSTN Trunks
switch/PBX
quality trunk
61
4. Site Preparation
SC
PBX
October 2005