ISO 20213:2015 pdf download.Space data and information transfer systems —Spacecraft onboard interface services - Message transfer service.
3 MESSAGE TRANSFER SERVICE
3.1.1.1 The Message Transfer Service shall implement the following requirements:
a) The Message Transfer Service shall implcmcnt ihc capability to send a mcssage to a designated destination service user in an asynchronous manner.
b) The Message Transfer Service shall implement the capability to receive a message sent to it from another service user.
c) The Messagc Transfer Service shall implement the capability to send a query message to and receive a reply message back from a designated destination service user in a synchronous manner.
d) The Message Transfer Service shall implement the capability to receive a query message from another service user and send back a reply message to a designated destination service user in a synchronous manner.
3.1.1.2 Optionally, the Message Transfer Service may implement the following requirements:
a) The Message Transfer Service may implement the capability to subscribe to receive messages published on a designated subject.
b) The Message Transfer Service may implement the capability to publish a message on a designated subject anonymously to a time-s’arng group of registered subscribers (destination users).
c) The Message Transfer Service may implement the capability to announce a message to a set of designated destination users.
3.1.1.1 The Message Transfer Service shall implement the following requirements:
a) The Message Transfer Service shall implcmcnt ihc capability to send a mcssage to a designated destination service user in an asynchronous manner.
b) The Message Transfer Service shall implement the capability to receive a message sent to it from another service user.
c) The Messagc Transfer Service shall implement the capability to send a query message to and receive a reply message back from a designated destination service user in a synchronous manner.
d) The Message Transfer Service shall implement the capability to receive a query message from another service user and send back a reply message to a designated destination service user in a synchronous manner.
3.1.1.2 Optionally, the Message Transfer Service may implement the following requirements:
a) The Message Transfer Service may implement the capability to subscribe to receive messages published on a designated subject.
b) The Message Transfer Service may implement the capability to publish a message on a designated subject anonymously to a time-s’arng group of registered subscribers (destination users).
c) The Message Transfer Service may implement the capability to announce a message to a set of designated destination users.
