Mission Operations Reference Model. Draft ... - CCSDS

DRAFT RECOMMENDED PRACTICE FOR MISSION OPERATIONS REFERENCE MODEL4.3.2 MESSAGE SENDING SEQUENCEFigure 4-5 shows the message sending sequence for the MO Service Layer. It includes theerror case as an alternative fragment.Consumer/ProviderApplicationMO Service LayerMALInvoke Service OperationBuild MAL MessageSubmit messagealt Error conditionReturn error conditionReturn error conditionReturn message okReturn message okFigure 4-5: MO Service Layer Sending Sequencea) The Application layer invokes a service-specific operation on the MO Service Layer.This may be an initial message from a consumer starting an interaction or from aprovider in response to a received message.b) The MO Service Layer constructs a MAL message that represents the service-specificoperation.c) The MO Service Layer then submits the message to MAL using its abstract serviceinterface.d) The MAL either returns an error condition due to a failure to send the message or aconfirmation that the message was sent successfully.NOTES1 This does not imply that it was received or accepted by the destination but merelythat the layers below the MO Service Layer accepted the message.2 Depending on the interaction pattern being used there may not be any furthermessages received for that operation from the destination.3 The error condition applies to the SEND interaction pattern for the case whereerrors are raised by the MAL or Transport layer itself.CCSDS 520.1-R-1 Page 4-6 October 2009