3Com Router 3000 Series Manual page 35

1-Port Channelized T3
MIM
3Com Router Release Notes for V1.20
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.
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.
1-Port Channelized T3 Module
Figure 22
35