Caution: If the 1-port channelized E3 module is connected to a cable that extends 
outside the building, you should install a lightning arrester at the input end of the 
cable to for lightning protection.
1 Power off the router.
2 Connect the SMB connector of an E3 or T3 cable to the Tx port of the 1-port 
channelized E3 module and the other end to the Rx port of the peer device. 
3 Connect the SMB connector of another E3 or T3 cable to the Rx port of the 1-port 
channelized E3 module and the other end to the Tx port of the peer device. 
4 Power on the router. 
5 Check the READY LED for the corresponding slot on the faceplate of the Router. 
ON means that the POST of the module has finished and the module can work 
normally. OFF means that the POST failed and you should contact your Service 
representative. 
6 Check the status of the synchronization LINK LED on the faceplate of the 1-port 
channelized E3 module. OFF means that faults occurred to the link and the signal 
synchronization failed. In this case, check the line. 
1-Port Channelized T3 
MIM
The main functions of the 1-port channelized T3 module include:
■ In T3 mode, the module can transmit, receive, and process one channel of T3 
fast traffic, as well as provide access to T3 traffic.
■ In CT3 mode, the module can provide subscribers with low-speed access at 
Nx64kbps or 56kbps, with N smaller than or equal to 128.
Note: T3 represents the tertiary group rate of T system in the TDM system, that is, 
44.736Mbps. A T3 channel can be channelized into 28 T1 channels through the 
demultiplexing processes of T23 and T12, with each T1 channel also supporting 
the operating modes of CT1. T23 is used to indicate either T2-to-T3 multiplex or 
T3-to-T2 demultiplex, and T12 to indicate T1-to-T2 multiplex or T2-to-T1 
demultiplex. T23 and T12 discussed here represent the demultiplex process.
Figure 22 illustrates the 1-Port Channelized T3 module.
Figure 22   1-Port Channelized T3 Module
3Com Router Release Notes for V1.20