3Com 3031 Command Reference Manual page 186

186 C 3: I M C
HAPTER NTERFACE ANAGEMENT OMMANDS
esf: Adopts ESF as the framing format for the T1-F interface.
Description
Using the ft1 frame-format command, you can configure the framing format for a
T1-F interface. Using the undo ft1 frame-format command, you can restore the
default framing format of the interface.
By default, T1-F interfaces use esf.
T1-F interfaces support SF and ESF. In SF, multiple frames can share the same frame
synchronization and signaling information, so that more significant bits can be
used for transmitting user data. In practice, the system test is often required. The
application of ESF technology can ensure normal service when system test is being
carried out.
Example
Set the framing format for the T1-F interface to SF.
[3com-Serial0/0/0] ft1 frame-format sf
ft1 loopback Syntax
ft1 loopback { local | remote }
undo ft1 loopback [ local | remote ]
View
T1-F interface view
Parameter
local: Places the interface in local loopback.
remote: Places the interface in remote loopback.
Description
Using the ft1 loopback command, you can configure a T1-F interface in local or
remote loopback. Using the undo ft1 loopback command, you can disable the
local and remote loopback on the interface.
By default, the interfaces are not placed in local or remote loopback.
Local loopback and remote loopback are used for testing the state of interface or
cable itself. These functions should be disabled in normal cases. On an interface,
using this command but with different arguments can respectively enable local
loopback and remote loopback, but these two functions cannot be enabled at the
same time.
Example
Place the T1-F interface in local loopback.