Could be 2 possibilities -

1) The cable between the router and the PBX is incorrect. A E1 cross over cable is normally used -

1 ---- 4

2 ---- 5

4 ---- 1

5 ---- 2

2) Based on the errors below, the framing may be incorrect. Try changing to CRC4 instead of the current NO-CRC4

E1 0/0/0 is down.

Applique type is Channelized E1 - balanced

Receiver has remote alarm.

alarm-trigger is not set

Version info Firmware: 20050620, FPGA: 15, spm_count = 0

Framing is NO-CRC4, Line Code is HDB3, Clock Source is Line Primary.

CRC Threshold is 320. Reported from firmware is 320.

Data in current interval (113 seconds elapsed):

0 Line Code Violations, 0 Path Code Violations

2 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins

2 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 82 Unavail Secs

Total Data (last 85 15 minute intervals):

2161758 Line Code Violations, 55883 Path Code Violations,

1304 Slip Secs, 5 Fr Loss Secs, 6 Line Err Secs, 0 Degraded Mins,

1305 Errored Secs, 0 Bursty Err Secs, 6 Severely Err Secs, 49876 Unavail Secs

E1 0/0/1 is down.

Applique type is Channelized E1 - balanced

Far End Block Errors Detected

Transmitter is sending remote alarm.

Receiver has loss of signal.