TCAP AC negotiation rules require that the proposed AC, if
acceptable, is reflected in the first backwards message.
If the AC
is not acceptable, and the TC-User does not wish to continue the
dialogue, it may provide an alternate AC to the initiator which can be
used to start a new dialogue.
TCAP AC negotiation applies only to
the SCF interfaces. Refer to ETS 300 287 [5] for a more detailed
description of the TCAP AC negotiation mechanism.
In some cases, it may be necessary to distinguish whether operations should be performed sequentially or in parallel (synchronised). Operations which may be synchronised are:
The method of indicating that operations are to be synchronised is
to include them in the same message. Where it is impossible to execute
one of the operations identified above until some other operation has
progressed to some extent or finished, the sending PE (usually SCP) can
control this by sending the operations in two separate messages.
This method does not imply that all operations sent in the same message
should be executed simultaneously, but simply that where it could make
sense to do so (in the situations identified above) the operations
should be synchronised.
In case of inconsistency between the above
mentioned generic rules and the FE-specific rules as specified in Clause
7, the FE-specific rules take precedence over the generic rules.