Specifications

Configure External T1 Channels

Configuring Serial Interfaces IC-83

Note If you select ami line coding, you must also invert the data on the T1 channel by using the

invert data interface command. To do so, ﬁrst use the interface serial

slot/port-adapter/port:t1-channel global conﬁguration command to select the T1 channel and enter

interface conﬁguration mode.

Note If you select sf framing, you should consider disabling yellow alarm detection because the

yellow alarm can be incorrectly detected with sf framing.

After you conﬁgure the T1 channels on the CT3IP, you can continue conﬁguring it as you would a

normal serial interface. All serial interface commands might not be applicable to the T1 channel. For

more information, refer to the “Conﬁgure a Synchronous Serial Interface” in this chapter.

To enter interface conﬁguration mode and conﬁgure the serial interface that corresponds to a T1

channel, use the following command in global conﬁguration mode:

Note The port adapter and port numbers for the CT3IP are 0.

In addition to the commands in the “Conﬁgure a Synchronous Serial Interface” section, the

invert data interface command can be used to conﬁgure the T1 channels on the CT3IP. If the T1

channel on the CT3IP is using AMI line coding, you must invert the data. For information on the

invert data interface command, refer to “Invert the Data” later in this chapter. For more information,

see the t1 linecode controller command.

Conﬁgure External T1 Channels

The ﬁrst three T1 channels (1, 2, and 3) of the CT3IP can be broken out to the DSUP-15 connectors

so the T1 channel can be further demultiplexed by the MIP on the same router, another router, or

other multiplexing equipment.

Note If a T1 channel that was previously conﬁgured as a serial interface is broken out to the

external T1 port, that interface and its associated conﬁguration remain intact while the channel is

broken out to the external T1 port. The serial interface is not usable during the time the T1 channel

is broken out to the external T1 port; however, the conﬁguration remains to facilitate the return of

the T1 channel to a serial interface with the no t1 external command.

Command Purpose

interface serial slot/port-adapter/port:t1-channel Deﬁne the serial interface for a T1 channel (values are

1 to 28) and enter interface conﬁguration mode.