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Locating Multichannel DS3 Alarms and Errors

 

Checklist for Locating Multichannel DS3 Alarms and Errors

Purpose

To check for the most common Multichannel DS3 alarms and errors encountered when investigating line problems on a Juniper Networks router.

Action

Table 1 provides links and commands for Multichannel DS3 alarms and errors.

Table 1: Checklist for MultichannelDS3 Alarms and Errors

Tasks

Command or Action

Display Alarms and Errors for Channelized DS3 to DS1 Interfaces

show interfaces t1-fpc/pic/port:channel extensive

Display Alarms and Errors for Channelized DS3 to DS0 Interfaces

show interfaces ds-fpc/pic/port:channel:channel extensive

Display Alarms and Errors for Channelized DS3 to DS1 Interfaces

Purpose

To display channelized DS3 to DS1 alarms and errors, use the following Junos OS command-line interface (CLI) operational mode command:

Action

Sample Output

user@host> show interfaces t1-2/1/0:19 extensive

Meaning

The sample output shows that there are no active alarms and active defects. When a major error (such as an alarm indication signal [AIS]) is seen for a few consecutive frames, a defect is declared within 1 second from detection. At the defect level, the interface is taken down and routing protocols are immediately notified (this is the default). In most cases, when a defect persists for 2.5 seconds plus or minus 0.5 seconds, an alarm is declared.

Notification messages are logged at the alarm level. Depending on the type of T1 alarm, you can configure the craft panel to display the red or yellow alarm LED and simultaneously have the alarm relay activate a physically connected device (such as a bell).Table 2 shows T1 media-specific alarms or defects that can render the interface unable to pass packets.

Table 2: T1 Media Alarms and Error Definitions

T1 Media Alarm or Error

Definitions

AIS

Alarm indication signal (blue alarm)

BEE

Block error event

BES

Bursty errored seconds

BPV

Bipolar violation

CS

Controlled slip

ES

Errored seconds

EXZ

Excessive zeros

LCV

Line code violation

LES

Line errored seconds

LOF

Loss of frame

LOS

Loss of signal

PCV

Path code violation

SEF

Severely errored frame

SEFS

Severely errored frame seconds

SES

Severely errored seconds

UAS

Unavailable seconds

YLW

Yellow alarm

See Checklist for T1 Alarms and Errors for more details on T1 alarms and statistics.

Display Alarms and Errors for Channelized DS3 to DS0 Interfaces

Purpose

To display T3 alarms and errors for channelized DS3 to DS0 interfaces, use the following Junos OS CLI operational mode command:

Action

Sample Output

user@host> show interfaces ds-2/1/0:5:1 extensive

Meaning

The sample output shows that there are no active alarms and active defects. When a major error (such as an AIS) is seen for a few consecutive frames, a defect is declared within 1 second from detection. At the defect level, the interface is taken down and routing protocols are immediately notified (this is the default). In most cases, when a defect persists for 2.5 seconds plus or minus 0.5 seconds, an alarm is declared.

Notification messages are logged at the alarm level. Depending on the type of T3 alarm, you can configure the craft panel to display the red or yellow alarm LED and simultaneously have the alarm relay activate a physically connected device (such as a bell).

Note

T3 is a general term used to refer to the transmission of 44.736-Mbps digital circuits over any media. T3 can be transported over copper, fiber, or radio. DS3 is the term for the electrical signal found at the metallic interface for this circuit where most of the testing is performed.

T1 Media Alarms and Error Definitions shows T3 media-specific alarms or errors that can render the interface unable to pass packets.

Table 3: T3 Interface Error Counter Definitions

T3 Alarm or Error

Definition

AIS

Alarm indication signal

EXZ

Excessive zeros

FERF

Far-end failures

IDLE

Idle code detected

LCV

Line code violation

LOS

Loss of signal

LOF

Loss of frame

YLW

Remote defect indication (yellow alarm)

PLL

Phase locked loop

See Checklist of Common T3 Alarms and Errors for more details on T3 alarms and statistics.