Motorola T1/E1 ユーザーズマニュアル

Canopy  T1/E1 Multiplexer 

 

 

 

 

 

 

September 2004 

 

 

 

 

 

 

     

      T1/E1 Multiplexer FPGA Version 3.4 

 
 

 

Page 25 of 73 

In a scenario where T1/E1 devices are configured with an external master clock source, 
each Canopy T1/E1 Multiplexer should be configured in Loopback Timing Mode.  Each 
Canopy T1/E1 Multiplexer will take the timing signal from the incoming T1/E1, derive the 
clock and then return the clock to the T1/E1 device.  The external clock source may be 
obtained from any number of sources including Carrier services, GPS, or other high-
quality clock source.   

For example, each of the two PBXs might have a SONET connection from the local 
telephone company operator. This connection would be used as the master clock source 
for both PBXs.  Alternatively, each PBX could have a Stratum 3 clock source from the 
same Central Office, or could be connected to GPS receivers. 

The Ethernet port to the Canopy BH module is a 100-Mbps full duplex port, transmitting 
at a throughput rate that does not cause buffer overload in the Canopy modules.  The 
LAN side Ethernet port, connected to the customer LAN, also transmits at 100 Mbps full 
duplex.  The Canopy T1/E1 Multiplexer will insert T1/E1 traffic into the Ethernet bit 
stream and therefore the Ethernet throughput will be reduced by approximately 2 Mbps 
for each T1/E1 that is programmed.  

The rates for Ethernet throughput for each programmed T1/E1 connection are displayed 
in 

1 

5.4 Mbps 

5.4 Mbps 

2 

4.1 Mbps 

2.66 Mbps 

3 

2.34 Mbps 

24 Kbps 

4 240 

Kbps 

N/A* 

 

 

NOTE: 
The maximum packet rate in T1 mode is 666 packets/sec.  The 
maximum packet rate in E1 mode is 442 packets/sec. Maximum 
Ethernet rate occurs when using 1518-byte packet streams.

 

Issue 3