By default, the T1 CSU supports 24 channels of 64 kb/s each (1.536 Mb/s), and the E1 CSU supports 30 channels of 64 kb/s each (1.92 Mbps). For applications that can support these arrangements, no additional configuration is required.
If you have been allocated less than the full T1/E1 bandwidth for your application, then you must specify which of the available channels you will be using.
Configurator Procedure for Configuring a T1 CSU or E1 CSU Interface
CLI Commands for Configuring a T1 CSU or E1 CSU Interface