There are two steps involved in configuring T1s for use on a router. The first step is the configuration of the CSU/DSUs. The second step is the configuration of the router interface. When using integrated CSU/DSUs, the lines might seem blurred, but the concepts remain the same. Configuring the router interface is just like configuring any serial interface.
To get a T1 up and operational, you must:
Encoding options are AMI and B8ZS. Data T1s should always use B8ZS encoding.
To configure encoding on a CSU/DSU WIC, use the
service-module t1 linecode interface command:
service-module t1 linecode b8zs
Framing options are D4/SF and ESF. Data T1s should always use ESF framing. To
configure framing on a CSU/DSU WIC, use the
service-module t1 framing interface command:
service-module t1 framing esf
If the T1 is being split or you have had fewer than 24 channels delivered to
you, you must tell the CSU/DSU how many channels are in use. This is done for the
CSU/DSU WIC with the
timeslots interface command. Here, I've specified that channels 7–12 will be used at a speed of ...