433 vcaindication 34331 function at the sending end

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Unformatted text preview: s a VCA.indication to the VCA Service user at the receiving end to deliver a VCA_SDU. NOTE – The VCA.indication primitive shall be the service indication primitive for the VCA Service. 3.4.3.3.2 Semantics The VCA.indication primitive shall provide parameters as follows: VCA.indication 3.4.3.3.3 (VCA_SDU, VCA Status Fields, GVCID, VCA_SDU Loss Flag (optional)) When Generated The VCA.indication primitive shall be passed from the service provider to the VCA Service user at the receiving end to deliver a VCA_SDU. 3.4.3.3.4 Effect On Receipt The effect of receipt of the VCA.indication primitive by the VCA Service user is undefined. 3.4.3.3.5 Additional Comments The VCA.indication primitive shall be used to deliver VCA_SDUs to the VCA Service user identified by the GVCID. 3.5 VIRTUAL CHANNEL FRAME SECONDARY HEADER (VC_FSH) SERVICE 3.5.1 OVERVIEW OF VC_FSH SERVICE The Virtual Channel Frame Secondary Header (VC_FSH) Service provides synchronous transfer of fixed-length data units in the Transfer Frame Secondary Header (FSH) of Transfer Frames of a Virtual Channel. The service is unidirectional and sequence-preserving. The transfer is synchronized with the release of Transfer Frames of a Virtual Channel. The service does not guarantee completeness, but it may signal gaps in the sequence of service data units delivered to the receiving user. CCSDS 132.0-B-1 Page 3-9 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL Only one user, identified with the GVCID of the Virtual Channel, can use this service on a Virtual Channel. Service data units from different users are not multiplexed together within one Virtual Channel. 3.5.2 VC_FSH SERVICE PARAMETERS 3.5.2.1 General The parameters used by the VC_FSH Service primitives shall conform to the specifications contained in subsections 3.5.2.2 through 3.5.2.4. 3.5.2.2 FSH_SDU NOTE – The FSH_SDU parameter is the service data unit transferred by the VC_FSH Service in the Frame Secondary Header of Transfer Frames of a Virtual Channel. For restrictions on the FSH_SDU transferred by the VC_FSH Service, see 3.2.4. 3.5.2.3 GVCID The GVCID para...
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This document was uploaded on 03/06/2014.

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