Motorola T1/E1 - Manual (Page 24)

Canopy T1/E1 Multiplexer September 2004
T1/E1 Multiplexer FPGA Version 3.4
Page 24 of 73
Figure 9: Slave timing set to Recovered mode
Network Timing Scenarios
Typically, when connecting two T1 devices, one end is set as the master clock source
and the other end is set as the slave clock source. The slave device takes the timing
information from the master clock source. The slave device then synchronizes its clocks
with the master. This is shown in
Figure 10 .
Figure 10: Network timing scenarios
When a Canopy T1/E1 Multiplexer is inserted between two T1 devices, the clocking
should be configured in the same manner as it would be without the Canopy T1/E1
Multiplexer. For example, when the Canopy T1/E1 Multiplexer is inserted between the
two PBXs, the one PBX will remain as the master clock source and the other PBX will
remain as the slave clock source. The Canopy T1/E1 Multiplexer should be configured in
the following manner:
◦ The Canopy T1/E1 Multiplexer connected to the master clock source should be
configured in Loopback Timing Mode. The unit will take the clock signal from the
PBX master clock source on the PBX transmit side, derive the clock and then
send it back to the PBX on the receive side.
◦ The Canopy T1/E1 Multiplexer connected to the slave clock source should be
configured in Recovery Timing Mode. It will derive a clock signal from the
incoming bit stream from the WAN side and pass it on to the slave PBX.
Issue 3