3Com manual Dual T1/PRI Status Displays

Dual T1/PRI Status Displays 4-7

■Unavailable Secs

The DS1 is determined to be unavailable. All other counters will stop. Any layer 1 condition or 10 consecutive SES events will lead to DS1 unavailability. Ten consecutive non-SESs (no alarm condition) will clear the unavailability.

■Bipolar Violations

This indicates bipolar violations (BPV) in the line format being used. A BPV occurs when two consecutive non-zero elements of the same polarity occur in an alternate mark inversion (AMI) signal.

■Framing Bit Errors

This indicates an error in the framing bit used to determine frame alignment. The framing bit error count is reported.

■Change in Frame Alignment (CFA)

This indicates that a receiver has reframed on a new framing pattern, and synchronized at a new frame alignment due to an OOF condition. The status report indicates whether or not a CFA occurred. A counter records the number of times a CFA occurred since the latest counter reset.

■Controlled Slip Secs (Frame Slips)

■

■

These are caused either by frames deleted due to buffer overflow (BOF) or frames repeated due to buffer underflow (BUF). The status report indicates whether or not a BOF or BUF condition occurred. A counter records the number of times a condition occurred since the latest counter reset.

Severely Err Framing Secs (SEFS)

Any second with an OOF or AIS condition is counted as an SEFS.

Bursty Errored Seconds

This occurs in ESF format only. It reports CRC error conditions in seconds.

■CRC Errors

This occurs only in ESF format when a CRC bit is in error. The CRC error count is reported.