E1-F Interface 139
By default, the frame format of CT1/PRI interface is ESF.
8Enable/disable internal loopback/external loopback
The interface needs to be set to internal loopback or external loopback when
during the test on some special functions.
Perform the following configurations in CT1/PRI interface view.
Tabl e 146 Enable/disable the internal loopback/external loopback of the CT1/PRI
By default, the functions of internal loopback and external loopback are disabled
on the CT1/PRI interfaces.
Display and Debug
CT1/PRI Interface Perform the following configurations in all views to display the status and related
information of the CT1/PRI interface, so as to monitor and maintain it.
Tabl e 147 Display and debug CT1/PRI interface
Generally, CT1/PRI interfaces are applied to the dedicated line and dial-up services.
For the typical configuration example and troubleshooting, refer to the
configurations of protocols at each layer and dialing configurations in this manual.
E1-F Interface E1-F interface is fractional E1 interface, and it is respectively simplified CE1/PRI
interface. If there is no need to use multiple channel sets or if ISDN PRI is not
necessary in an E1 application, it is too much to use CE1/PRI interface. At this time,
E1-F interface is more than enough for meeting the simple E1 access
requirements. Compared with CE1/PRI interface, E1-F interface is a nice low-cost
choice for E1 access.
Compared with CE1/PRI interfaces, E1-F interface has the following features:
■When working in framed mode, E1-F interface can only bind time slots into
one channel set, but CE1/PRI interface can group timeslots randomly and bind
them into multiple channel sets.
■E1-F interface does not support PRI operating mode.
E1-F interface can work in both framed and unframed modes.
When it works in unframed mode, it is a timeslot-less interface of 2048kbps data
bandwidth. In this case, it is logically equivalent to a synchronous serial interface,
Set the frame format of CT1/PRI interface frame-format { sf | esf }
Restore the frame format of CT1/PRI interface
to the default value undo frame-format
Operation Command
Enable the internal loopback/external loopback of the
CT1/PRI loopback { remote | local }
Disable the internal loopback/external loopback of the
CT1/PRI undo loopback { remote |
local }
Operation Command
Display the operating status of the CT1/PRI
interface display controller t1
interface-number
Display the operating status of the channel set
or pri set display interfaces serial
interface-number:number