Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Locating Channelized OC12 Alarms and Errors

 

Checklist for Channelized OC12 Alarms and Errors

Purpose

To check the most common Channelized OC12 alarms and errors encountered when investigating line problems on a Juniper Networks router.

Action

Table 1 provides links and commands for Channelized OC12 alarms and errors.

Table 1: Checklist for Channelized OC12 Alarms and Errors

Tasks

Command or Action

Display Channelized OC12 Alarms and Errors

show interfaces t3-fpc/pic/port:channel extensive

Display Channelized OC12 IQ Alarms and Errors

show interfaces interface-type-interface-name extensive

Display Channelized OC12 Alarms and Errors

Purpose

To display Channelized OC12 interface alarms and errors, use the following Junos OS command-line interface (CLI) operational mode command:

Action

Sample Output 1

user@host> show interfaces t3-0/3/0:0 extensive

Meaning

The sample output shows that there are no active alarms or active defects, either with the T3 media or the SONET layer. If alarms or errors occur, you must troubleshoot the T3 media or the SONET layer. For more information on diagnosing a T3 media problem or a SONET layer problem, see the topics in the Related Topics section.

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 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.

Table 2 shows T3 media-specific alarms or errors that can render the interface unable to pass packets.

Table 2: 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

For more details on T3 alarms and statistics, see Checklist of Common T3 Alarms and Errors.

Display Channelized OC12 IQ Alarms and Errors

Purpose

To display Channelized OC12 IQ interface alarms and errors, use the following Junos OS CLI operational mode command:

Action

Sample Output 1

The following sample output is for a controller interface:

Sample Output 2

The following sample output is for a T1 channel on a Channelized OC12 IQ interface:

Meaning

The sample output shows that there are no active alarms or active defects. If alarms or errors occur, you must troubleshoot the channel media or the SONET layer. For more information, see the topics that correspond to the media with which you are working.

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.