Space Link Extension - Service Management - CCSDS

DRAFT RECOMMENDED STANDARD FOR SPACE LINK EXTENSION SERVICE MANAGEMENT
If the Invocation message passes message set validation, the Performer starts a local
disposition timer (based on the messageTimestamp value of the Invocation
message, the value of the urgent parameter and the associated timeout value in the Service
Agreement, and the expected message transit time for a return message to the Invoker (see
Note 1, below) and performs service management validation on the invocation. The details
of service management validation are specific to each operation, and are specified in the
associated Invoker and Performer requirements for each operation.
NOTES
1 In order for the Performer to ensure that any return to an Invocation arrives at the
Invoker before the Invoker’s disposition timer expires, the Performer must adjust
(i.e., shorten) its local disposition timer value by some amount of time to compensate
for the transit of the return across the communications network that connects them.
The method by which the Performer determines this adjustment factor is outside the
scope of this Recommended Standard.
2 It is assumed that the time standards upon which the Invoker and Performer set their
disposition timers are synchronized to within one (1) second of each other. If this
assumption cannot be made for a particular pair of Invoker and Performer, then
additional methods may be required to compensate for the ambiguity (such as further
decreasing the Performer’s disposition timer value to account for the ambiguity). Any
such adjustment for time standard ambiguity is outside the scope of this
Recommended Standard.
If the Invocation is valid at the service management level and the operation can be
performed before the disposition timeout is reached, the Performer performs the invoked
operation and returns a SuccessfulReturn message to the Invoker’s message set port.
The details of the performance of the operation and the information returned as part of the
result are operation-specific. The Performer may perform local functions specific to a
successful operation as part of completing the operation procedure.
If the Invocation is not valid at the service management level, or if the Performer cannot
complete service management validation before its disposition timer expires, the Performer
completes the operation procedure and returns a FailedReturn or FailedReturn-
WithDenial message to the Invoker’s message set port such that the Invoker receives the
result before the disposition timer expires. Whether it is a FailedReturn or a Failed-
ReturnWithDenial that is returned depends on the specific operation. In the remainder
of this Recommended Standard, the term FailedReturn* is used to designate a message
that conforms to either the or
message stereotype. Each FailedReturn* message contains operation-specific
diagnostic information. The Performer may perform local functions specific to a failed
operation as part of completing the operation procedure.
Upon receipt of an UnrecognizedMessageSetResponse or InvalidMessage-
Response, the Invoker validates exception response in accordance with the Receive and
CCSDS 910.11-R-2 Page 3-38 March 2008