3.5 TL1 Autonomous Message

Autonomous messages are output messages sent by the NEs to report alarms, performance data, configuration changes, or condition changes. Messages relating to alarm conditions are spontaneously triggered by the NE without intervention. Messages relating to periodic reporting of performance data values are scheduled by the operator.

Autonomous message has the following format
header auto_id [text_block] terminator

3.5.1 Header

Autonomous message’s header block take the following form:
^^^sid^year-month-day^hour:min:sec

Here, SID is the source identifier, year-month-day and hour:min:sec represent the date and time of the message.

SID
Source identifier represents the name of the NE used for identifying the NE emitting the message. SID is similar to the target identifier.

3.5.2  Auto ID

Autonomous identifier block has the following format
alarm_code^atag^verb [-modifier1[-modifier2]]

Alarm Code

Alarm code indicates the severity of the alarm. One of the four severity levels, given below in the table, is assigned to every event condition.

Alarm Code (almcde)	Description	Corresponding Notificatin Code (ntfncde)
*C	Critical Alarm Condition	CR
**	major Alarm Condition	MJ
*^	Minor Alarm Condition	MN
A^	Non-Alarmed autonomous Message	CL, NA

If multiple alarms are reported, the alarm code will correspond to the alarm with the highest severity. Non-alarmed code is used when the NE reports non-alarmed autonomous messages such as those reporting performance data measurements.

ATAG

Every TL1 autonomous message, that the NE generates autonomously, contains a unique identifier called the Autonomous TAG (ATAG). It is an integer value (e.g., 198) incremented by one for each message. These ATAGs can be used for alarm correlation. The OSS can look for the continuity of the ATAG values and verify that no message is lost. If the OSS senses an ATAG out of sequence, it can request the missing data to be sent again from the NE.

• Fractional ATAG : Sometimes ATAG may be associated with a second decimal, component. It helps in correlating multiple events with a single source (e.g., 198.7).

•   ATAG character length GR-833 specifies the character length of ATAG to be maximum of 10 characters including the fractional component.

VMM

VMM represents the verb-modifier1-modifier2 format or the command code. The verb indicates the action to be taken on the NE, as requested by the TL1 command, or the type of autonomous event that is fired by the NE. The modifiers further qualify the command as to which object is acted upon by the command and give additional description about the object.

3.5.3 Text Block

Text blocks hold the main body of the output message and the payload. Text blocks have quoted lines, unquoted lines, and comments

• An unquoted line is made up of a list of parameters (either name defined or position defined) separated by mandatory white spaces or optional commas.
  
• A quoted line consists of a double quoted (") line of machine parsable text.
  
• A comment allows free form text messages to be generated by the NE for presentation to the OS. The comment must begin with /* and end with */.

3.5.4 Terminators

Syntax of terminators: <cr><lf>( ; | > )