3Com 10014299 manual Set line clock for a T1-F interface, Set frame format of T1-F interface

T1-F Interface 145

If T1-F interface is used as DCE, the slave clock should be selected. If it is used as DTE, the master clock should be selected.

If the T1-F interfaces of two routers are directly connected, they must respectively work in slave and master clock modes. If the T1-F interface of the router is connected to an exchange, however, the exchange is working as DCE and provides clock, so the interface of the router should work in master clock mode.

Perform the following configuration in T1-F interface view.

Table 160 Set line clock for a T1-F interface

Operation	Command
Set line clock for a T1-F interface	ft1 clock { master
	slave }
Restore the line clock of the T1-F interface to the default	undo ft1 clock
setting

By default, the clock of T1-F interface is slave clock.

6Set Interface Frame Format

T1-F interfaces support Supper Frame (SF) and Extended Supper Frame (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 the system test is being carried out.

Perform the following configuration in T1-F interface view.

Table 161 Set frame format of T1-F interface

Operation	Command
Set frame format for a T1-F interface	ft1	frame-format { sf
	esf	}
Restore the default frame format of T1-F interface	undo ft1 frame-format

By default, the frame format of T1-F interface is ESF.

7Enable or Disable Local Loopback/Remote Loopback

An interface should be place in local loopback or remote loopback for some special functionality tests.

Perform the following configuration in T1-F interface view.

Table 162 Enable/Disable local/remote loopback on a T1-F interface

Operation	Command
Enable local/remote loopback on an interface	ft1 loopback { local
	remote }
Disable local/remote loopback on an interface	undo ft1 loopback [
	local remote ]

By default, no T1-F interface is placed in local or remote loopback.

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.