DS3 performance monitoring parameters

Overview

This section describes the performance monitoring parameters that are monitored on DS3 signals incoming from the high speed fiber and from the local DSX-3 cross-connect.

In order to generate DS3 PM reports, the port Primary State must be IS (in service). (When the PST parameter is provisioned as AUTO and a valid DS3 signal is detected, the PST parameter automatically transitions to the IS state.) The VM mode should be off because the P-bits can be corrected at nodes where the VM Mode is provisioned on, and the DS3 P-bit PM data may not provide a complete report of the end-to-end DS3 path errors.

Monitored parameters

The following table lists the DS3 line and path performance parameters that Alcatel-Lucent 1850 TSS-5 monitors, including the default and ranges for the 15-minute and 1-day (24-hour) registers.

Table 5-65: DS3 performance parameters

Facility	Measured Provisionable Parameter	15-Min		1-Day
Facility	Measured Provisionable Parameter	Default	Range¹	Default	Range¹
DS3 Line	Coding Violations (CV-L)	387	0–16383	3865	0–1048575
	Errored Seconds (ES-L), ES-L FE	25	0–900	250	0–65535
	Severely Errored Seconds (SES-L)	4	0–900	40	0–65535
DS3 Path	Coding Violations (CV-P)Coding Violations Far End (CV-PFE)	382	0–16383	3820	0–1048575
	Errored Seconds (ES-P)Errored Seconds Far End (ES-PFE)	25	0–900	250	0–65535
	Severely Errored Seconds (SES-P) Severely Errored Seconds Far End (SES-PFE)	4	0–900	40	0–65535
	Unavailable Seconds (UAS-P)Unavailable Seconds Far End (UAS-PFE)	10	0–900	10	0–65535
	SE Frame/Alarm Indication Signal Seconds (SAS-P) SE Frame/Alarm Indication Signal Seconds Far End (SAS-PFE)	2	0–900	8	0–65535

Notes:

When an individual performance monitoring parameter threshold is provisioned as zero (0), TCA reporting for the affected parameter is disabled.

DS3 line parameters

Alcatel-Lucent 1850 TSS-5 monitors the following ingress near end DS3 line parameters on incoming (from the DSX-3 cross-connect) DS3 signals. Ingress refers to performance monitoring parameters that are measured at the input of the DS3 circuit pack on the DS3 line side (also referred to as facility, customer terminal, or DSX side).

Supported performance monitoring signal formats

Alcatel-Lucent 1850 TSS-5 supports DS3 line performance monitoring on DS3 signals with P-bit parity, FM-bit parity, or CP-bit parity performance monitoring signal formats.

Coding violations (CV-L)

The near end CV-L parameter increments once for each bipolar violation (BPV) and excessive zeros (EXZ) detected at the DS3 line layer.

Errored seconds (ES-L)

The near end ES-L parameter increments once for each second during which Alcatel-Lucent 1850 TSS-5 detects either one or more bipolar violations (BPVs) or excessive zeros (EXZ), or one or more LOS defects.

Severely errored seconds (SES-L)

The near end SES-L parameter increments once for each second during which Alcatel-Lucent 1850 TSS-5 detects either one or more LOS defects, 2444 or more BPVs at a minimum BER of 7.5 X 10^-5, or 45 or more BPVs at a minimum BER of 1 X 10^-6.

DS3 line PM report

Use the Performance → View PM Reports → DS3 Line command to obtain the DS3 Line PM Report. Ingress near end DS3 line PM is reported with an AID of the DS3 interface and a modifier of T3.

DS3 path performance monitoring signal format

Alcatel-Lucent 1850 TSS-5 supports the following DS3 path performance monitoring signal formats:

P-bit parity: The P bits are monitored for detecting code violations at the near end.
FM-bit parity: The F and M bits are monitored for detecting code violations at the near end.
CP-bit parity: CP-bit parity is used for end-to-end DS3 path PM (near end and far end). The C bits are monitored for code violations. CP-bit parity is only allowed on DS3 signals with the C-bit signal format.

P-bit parity

When provisioned for P-bit parity, Alcatel-Lucent 1850 TSS-5 calculates and provides counts of the following near end DS3 path parameters incoming from the fiber or DSX-3:

Coding violations (CV-P)
Errored seconds (ES-P)
Severely errored seconds (SES-P)
Unavailable seconds (UAS-P)
Severely errored frame/alarm indication signal seconds (SAS-P)

FM-bit parity

FM-bit parity provides an alternative method for determining and accumulating DS3 path performance data based on an error estimation technique using errors on the F&M framing bits to approximate the actual error counts in the DS3 path payload.

Adjusted F&M bit performance monitoring estimates the following near end DS3 path parameters incoming from the fiber or DSX-3:

Coding violations (CV-P)
Errored seconds (ES-P)
Severely errored seconds (SES-P)
Unavailable seconds (UAS-P)
Severely errored frame/alarm indication signal seconds (SAS-P)

CP-bit parity

When provisioned for CP-bit parity, Alcatel-Lucent 1850 TSS-5 calculates and provides counts of the following DS3 near end and far end path parameters incoming from the fiber or DSX-3:

Coding violations (CV-P)
Errored seconds (ES-P)
Severely errored seconds (SES-P)
Unavailable seconds (UAS-P)
Severely errored frame/alarm indication signal seconds (SAS-P)

Violation monitoring and removal

The DS3 path performance monitoring signal formats support provisionable P-bit monitoring and correction (violation monitoring mode) on the outgoing DS3 signal toward the DS3 facility.

The following table shows the provisionable DS3 signal formats, performance monitoring signal formats, and VM modes.

Table 5-66: DS3 signal formats, PM signal formats, and VM modes

DS3 Signal Format	Performance Monitoring Signal Format	VM Mode	Monitor P-Bits	Correct P-Bits
C-Bit	P-bit parity	On	X	X
	P-bit parity	Off	X
	FM-bit parity	On		X
	FM-bit parity	Off
	CP-bit parity	On		X
	CP-bit parity	Off

Near end DS3 path parameters

Alcatel-Lucent 1850 TSS-5 monitors the following ingress and egress near end DS3 path parameters at the local network element. Ingress refers to parameters that are measured on incoming DS3 signals at the input of the local DS3 circuit pack on the DS3 line side (also referred to as facility, customer terminal, or DSX side). Egress refers to parameters that are measured on incoming DS3 signals at the input of the local DS3 port unit on the SONET side (also referred to as fiber side).

Coding violations (CV-P)

The near end CV-P parameter increments once for each parity error detected at the path level. The CV-P parameter applies to all performance monitoring signal formats.

In the P-bit parity signal format, non-identical P-bits corresponding to the same DS3 M-frame also increment the CV-P parameter.

For CP-bit parity signal format, the three C-bits in subframe 3 of a C-bit formatted DS3 frame carry the DS3 path-parity information. At the DS3 transmitter, the CP bits in the DS3 C-bit frame are set equal to the two P-bits in frame "n". These CP bits are then inserted into frame "n+1". Since the CP bits are not modified in any way while passing through the network, the DS3 receiver can determine if errors occurred in the DS3 path. The DS3 receiver computes the parity of frame "n" and compares that parity with the value received in the CP bits in frame "n+1". If the values do not match, DS3 path parity violations are counted.

Errored seconds (ES-P)

The near end ES-P parameter increments once for each second during which Alcatel-Lucent 1850 TSS-5 detects either one or more parity errors, one or more SEF defects, or one or more AIS defects. The ES-P parameter applies to all performance monitoring signal formats.

Severely errored seconds (SES-P)

The near end SES-P parameter increments once for each second during which Alcatel-Lucent 1850 TSS-5 detects either one or more AIS or SEF defects, 2444 or more BPVs at a minimum BER of 7.5 X 10^-5, or 45 or more BPVs at a minimum BER of 1 X 10^-6. The SES-P parameter applies to all performance monitoring signal formats.

Unavailable seconds (UAS-P)

A near end UAS-P is a second during which the path is unavailable. A path is considered unavailable from the beginning of 10 consecutive severely errored seconds until the beginning of 10 consecutive seconds, none of which are severely errored. The UAS-P parameter applies to the P-bit parity and FM-bit parity performance monitoring signal formats.

Severely errored frame/alarm indication signal seconds (SAS-P)

The SAS-P parameter increments once for each second during which Alcatel-Lucent 1850 TSS-5 detects either one or more severely errored frame defects, or one or more AIS defects. The SAS-P parameter applies to all performance monitoring signal formats.

Near end DS3 path PM report

Use the Performance → View PM Reports → DS3 Path command to obtain the DS3 Path PM Report. Ingress near end DS3 path PM is reported with an AID of the DS3 interface and a modifier of T3. Egress near end DS3 path PM is reported with an AID of the SONET interface and a modifier of T3.