The table hwXdslTR129LineConfProfModeSpecTable extends the XDSL line configuration profile by XDSL Mode Specific parameters. A row in this table that has an index of hwXdslTR129LineConfProfMode == defMode(1), is called a 'mandatory' row. A row in this table that has an index such that hwXdslTR129LineConfProfMode is not equal to defMode(1), is called an 'optional' row. When a row in the hwXdslTR129LineConfProfTable table (the parent row) is created, the SNMP agent will automatically create a 'mandatory' row in this table. When the parent row is deleted, the SNMP agent will automatically delete all associated rows in this table. Any attempt to delete the 'mandatory' row using the hwXdslTR129LineConfProfModeSpecRowStatus attribute will be rejected by the SNMP agent. The manager MAY create an 'optional' row in this table using the hwXdslTR129LineConfProfModeSpecRowStatus attribute if the parent row exists. The manager MAY delete an 'optional' row in this table using the hwXdslTR129LineConfProfModeSpecRowStatus attribute at any time. If the actual transmission mode of a DSL line does not match one of the 'optional' rows in this table, then the line will use the PSD configuration from the 'mandatory' row. The indexes of this entry are hwXdslTR129LineConfProfProfileName and hwXdslTR129LineConfProfMode.