Configuring a T1-F Interface
To use a low-rate (512 kbit/s for example) T1 channel to transmit services, configure a T1-F interface.
Pre-configuration Tasks
Before configuring a T1-F interface, complete the following task:
Install a 1E1T1-F/2E1T1-F interface card on the router and ensure that it is registered successfully.
Context
T1-F interfaces on both ends must be configured with the same parameters except for the clock mode. Otherwise, devices on both ends cannot communicate properly.
Procedure
- Run system-view
The system view is displayed.
- Configure the 1E1T1-F/2E1T1-F interface card to work in T1-F mode.
Run display device
Information about the 1E1T1-F/2E1T1-F interface card is displayed. You can check the slot ID of the interface card, whether the interface card is installed in the slot, and whether it is working properly.
Run display workmode { slot slot-id | all }
The working mode of the 1E1T1-F/2E1T1-F interface card is displayed.
Run set workmode slot slot-id e1t1-f t1-f
The 1E1T1-F/2E1T1-F interface card is configured to work in T1-F mode.
By default, a 1E1T1-F/2E1T1-F interface card works in E1-F mode.
After completing this step, reset the 1E1T1-F/2E1T1-F interface card and wait for a while for the configuration to take effect.
The 4E1T1-F/8E1T1-F interface card only works in E1-F mode and does not support working mode switching.
- Run interface serial interface-number
The T1-F interface view is displayed.
- Run ft1 timeslot-list list [ speed { 56k | 64k } ]
The timeslots to be bundled and timeslot rate are specified.
By default, all the 24 timeslots of a T1-F interface are bundled to form a channel set, and the timeslot rate is 64 kbit/s. That is, the default T1-F interface rate is 1536 kbit/s.
- Configure other parameters on the T1-F interface.
Run description text
The interface description is configured.
Run ft1 cable { long { -7.5db | -15db | -22.5db } | short { 133ft | 266ft | 399ft | 533ft | 655ft } }
The transmission line attenuation is set.
The default attenuation of the transmission line on a T1-F interface is -7.5 dB.
Run ft1 clock { master | slave | system }
The clock mode is set.
By default, a T1-F interface works in slave clock mode and uses line clock signals from the master clock. When T1-F interfaces of two devices are directly connected, one T1-F interface must work in master clock mode and the other in slave clock mode.
Run crc { 16 | 32 | none }
The CRC mode is set.
By default, a T1-F interface uses 16-bit CRC.
Run ft1 alarm-threshold { ais { level-1 | level-2 } | lfa { level-1 | level-2 | level-3 | level-4 } | los { pulse-detection value | pulse-recovery value } }
Alarm thresholds are set.
The default alarm thresholds are as follows:- Alarm indication signal (AIS) alarm: level-1.
- Loss of frame alignment (LFA) alarm: level-1.
- Loss of Signal (LOS) alarm: The value of pulse-detection is 176 and the value of pulse-recovery is 22, indicating that a LOS alarm is generated if less than 22 pulses are detected within 176 pulse intervals.
Run ft1 idlecode { 7e | ff }
The line idle code is set.
By default, a T1-F interface uses the line idle code 0x7e.
Run ft1 frame-format { esf | sf }
The frame format is configured.
By default, a T1-F interface uses the extended super frame (ESF) format.
Run ft1 itf { number number | type { 7e | ff } }
The interframe filling tag and the number of interframe filling tags are set.
By default, a T1-F interface uses the interframe filling tag 0x7e and sends four filling tags between two frames.
Run ft1 data-coding { inverted | normal }
Data inversion is configured.
By default, a T1-F interface does not invert data.
Run ft1 detect-rai
RAI detection is enabled.
By default, RAI detection is enabled on a T1-F interface.
