The tags and their associated attributes are built into information elements
(IEs) for the transmission of ISDN messages on the line.
Note: The complete set of tags described below are not supported
by every ISDN protocol. For information about the tags supported by a specific
protocol, see
ISDN tag support for specific protocols.
Further information about CLGN, CLGN2, CLDN, REDIRN and ORIGIN and their attributes:
- The attributes NUMBER_TYPE and NUMBER_PLAN must be paired together,
and are formed into octet 3. They must be present in all tags except CLDN,
where if NUMBER_TYPE and NUMBER_PLAN are not present, they are taken
from the system ISDN configuration as normal.
- The attributes SCREEN and PRESENT must be paired together and are formed
into octet 3a. SCREEN and PRESENT are only valid if NUMBER_TYPE and NUMBER_PLAN
are also present.
- The attribute REDIR_REASON is formed into octet 3b. It is only valid
if the pairings of SCREEN and PRESENT, and NUMBER_TYPE and NUMBER_PLAN
are also present.
- The attributes CF and REDIRECT_COUNTER must be paired together and
are formed into octet 3c. They are only valid if REDIR_REASON, SCREEN and
PRESENT, and NUMBER_TYPE and NUMBER_PLAN are all also present.
- If the PRESENT attribute is set to presentation restricted, the TAG is only sent back to the state table if the ‘Allow incoming
numbers with presentation restricted’ system parameter is set to enabled in the ISDN system.
- If formatting errors are detected in either tag or attribute values, yellow
alarm error # 29221 is generated, and provides appropriate information
relating to the error. Tags found to be in error are not transmitted.
- The Blueworx Voice Response ISDN code sets the appropriate extension bits when an informaton
element (IE) is built.