3Com 3031 Command Reference Manual page 193

Fundamental CE3 Interface Configuration Commands 193
If an E1 line encapsulated with PPP has been set to perform loopback, it is normal
for the state of the link layer protocol to be reported as DOWN.
Example
Set the loopback mode of the first E1 line on the E3 interface to local.
[3com-E3 1/0/0]e1 1 set loopback local
e1 shutdown
Syntax
e1 line-number shutdown
undo e1 line-number shutdown
View
CE3 interface view
Parameter
line-number: E1 line number in the range of 1 to 16.
Description
Using the e1 shutdown command, you can shut down an E1 line on the CE3
interface. Using the undo e1 shutdown command, you can enable the E1 line.
By default, E1 line is enabled.
This command will affect not only the specified E1 line but also the serial
interfaces formed by bundling the timeslots of the E1 line. Executing the e1
shutdown command on the specified E1 line will shut down all these serial
interfaces and the data transmission and receiving will be stopped as a result.
Likewise, executing the undo e1 shutdown command will re-enable all these serial
interfaces.
Example
Shut down the first E1 line on the E3 interface.
[3com-E3 1/0/0]e1 1 shutdown
e1 unframed
Syntax
e1 line-number unframed
undo e1 line-number unframed
View
CE3 interface view
Parameter
line-number: E1 line number in the range of 1 to 16.