For a T1 or E1 PRI troubleshooting, follow the following steps.
- show controllers [t1 | e1]
- Check most of the PRI fields by this show controllers command.
- Ensure that line coding, framing, and clock source are configured and match the settings set by your Service Provider
- Line Coding
- T1 - Bipolar-8 Zero Substitution (B8ZS) and Alternate Mark Inversion (AMI)
- B8ZS - (also called Clear Channel and Binary 8 Zero Substitution) replaces each string of 8 consecutive zeros with the special pattern "000VB0VB"
- AMI - Each successive mark is inverted and the average or DC level of the line is therefor zero
- E1 - High Density Bipolar of Order 3 (HDB3)
- Framing
- T1 - Super Frame (sf) and Extended Super Frame (esf) - not compatible with each other
- Super Frame - consists of 12 consecutive 193-bit frames
- Extended Super Frame - consists of 24 consecutive 193-bit frames
- E1 - framing crc4 (cyclic redundancy check) and no-crc4
- Check if the line is down
- Make sure the controller is NOT administratively down. Perform a "no shut" command on the Controller interface.
- Check for reported alarms
- Use the show controllers command to see if there are any alarms on the controller.
- Receive Alarm Indication Signal (BLUE)
- Check for error events
- Check if the interface is T1 or E1 CAS, E1 R2, or PRI
show controllers t1
T1 0/3/0 is up.
Applique type is Channelized T1
Cablelength is long 0db
Description: Qwest LongDist #4 CID DS1-1234567
No alarms detected.
alarm-trigger is not set
Soaking time: 3, Clearance time: 10
AIS State:Clear LOS State:Clear LOF State:Clear
Version info Firmware: 20100222, FPGA: 13, spm_count = 0
Framing is ESF, Line Code is B8ZS, Clock Source is Line.
CRC Threshold is 320. Reported from firmware is 320.
Data in current interval (155 seconds elapsed):
0 Line Code Violations, 0 Path Code Violations
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Total Data (last 24 hours)
0 Line Code Violations, 0 Path Code Violations,
0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
