3Com 9000 manual Physical Layer Statistics

Physical Layer Statistics 191

Table 27 Physical Layer Statistics

Statistic Description

SONET section level BIP errors (B1)

Section BIP-8 - bit-interleaved parity code 8 - even parity for error monitoring

SONET section level BIP errors (B2)

SONET section level BIP errors (B3)

SONET loss of signal state (LOS)

SONET loss of frame state (LOF)

SONET loss of pointer state (LOP)

SONET out of cell delineation state (OCD)

Line BIP-8 - line error monitoring

Path BIP-8 - path error monitoring

Loss of signal. The loss of signal defect is declared when no transitions are detected on the incoming signal (before descrambling). The LOS defect is detected upon observing 2.3 to 100 microseconds of no transitions. The defect is cleared after a 125 microsecond interval (one frame) during which no LOS defect is detected.

Loss of frame. A loss of frame defect is declared when an OOF/SEF defect persists for a period of 3 milliseconds. The LOF defect is terminated when the incoming signal remains continuously in-frame for a period of 1 ms to 3 ms.

Loss of pointer. A loss of pointer defect is declared when either a valid pointer is not detected in eight consecutive frames, or when eight consecutive frames are detected with the New Data Flag (NDF) set to “1001” without a valid concatenation indicator. A LOP defect is terminated when either a valid pointer with a normal NDF set to “0110”, or a valid concatenation indicator is detected for three contiguous frames.

SONET path alarm indication signal state (Path AIS)	The AIS is an all-ONES characteristic or adapted information
SONET line alarm indication signal state (Line AIS)	signal. It is generated to replace the normal traffic signal
	when it contains a defect condition in order to prevent
	consequential downstream failures being declared or alarms
	being raised.
	AIS can also be identified as:
	- AIS-L (Line Alarm Indication Signal)
	- SP-AIS (STS Path Alarm Indication Signal)
	- VP-AIS (VT Path Alarm Indication Signal)
SONET line remote defect indication state (Line RDI)	A signal returned to the transmitting Terminating Equipment
SONET path remote defect indication state (Path RDI)	upon detecting a Loss of Signal, Loss of Frame, or AIS defect.
	RDI was previously known as FERF.
	RDI can also be identified as:
	- RDI-L (Line Remote Defect Indication)
	- RDI-P (STS Path Remote Defect Indication)
	- RDI-V (VT Path Remote Defect Indication)