3Com V6100, User Manual Manual, Page: 279 / 496

V6100 and V7122 User Guide
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HAPTER
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ONFIGURATION
V7122 Clock Settings
The gateway can either generate its own timing signals, using an internal clock, or recover
them from one of the E1/T1 trunks.
1 To use the internal gateway clock source configure the following parameters:
ƒ
TDMBusClockSource = 1
ƒ
ClockMaster = 1 (for all gateway trunks)
2
To use the recovered clock option, configure the following parameters:
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TDMBusClockSource = 4
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ClockMaster_x = 0 (for all ‘slave’ gateway trunks connected to PBX#1)
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ClockMaster_x = 1 (for all ‘master’ gateway trunks connected to PBX#2)
Assuming that the gateway recovers its internal clock from one of the ‘slave’ trunks
connected to PBX#1, and provides clock to PBX#2 on its ‘master’ trunks.
In addition it is necessary to define from which of the ‘slave’ trunks the gateway recovers its
clock:
ƒ
TDMBusPSTNAutoClockEnable = 1 (the gateway automatically selects one of the
connected ‘slave’ trunks)
Or
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TDMBusLocalReference = # (Trunk index: 0 to 7, default = 0)
To configure the TDM Bus Clock Source parameters, see Configuring SS7
Tunneling.
When the V7122 is used in a ‘non-span’ configuration, the internal gateway clock
must be used (as explained above).