Indication primitive is the service indication

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Unformatted text preview: follows: VC_OCF.indication (OCF_SDU, GVCID, OCF_SDU Loss Flag (optional)) CCSDS 132.0-B-1 Page 3-14 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL 3.6.3.3.3 When Generated The VC_OCF.indication primitive shall be passed from the service provider to the VC_OCF Service user at the receiving end to deliver an OCF_SDU. 3.6.3.3.4 Effect On Receipt The effect of receipt of the VC_OCF.indication primitive by the VC_OCF Service user is undefined. 3.6.3.3.5 Additional Comments The VC_OCF.indication primitive shall be used to deliver OCF_SDUs to the VC_OCF Service user identified by the GVCID. 3.7 VIRTUAL CHANNEL FRAME (VCF) SERVICE 3.7.1 OVERVIEW OF VCF SERVICE The Virtual Channel Frame (VCF) Service provides transfer of a sequence of fixed-length TM Transfer Frames of a Virtual Channel, created by an independent protocol entity, across a space link. The service is unidirectional, either asynchronous or periodic, and sequencepreserving. The service does not guarantee completeness, but it may signal gaps in the sequence of service data units delivered to the receiving user. 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. 3.7.2 VCF SERVICE PARAMETERS 3.7.2.1 General The parameters used by the VCF Service primitives shall conform to the specifications contained in subsections 3.7.2.2 through 3.7.2.4. 3.7.2.2 Frame The Frame parameter shall be a TM Transfer Frame of the Virtual Channel specified by the GVCID parameter. NOTES 1 The Frame parameter is the service data unit transferred by the VCF Service. CCSDS 132.0-B-1 Page 3-15 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL 2 The format of the GVCID parameter is defined in 4.1. 3 For restrictions on the TM Transfer Frames transferred by the VCF Service, see 3.2.6. 3.7.2.3 GVCID The GVCID parameter shall contain a GVCID that indicates the Virtual Channel th...
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This document was uploaded on 03/06/2014.

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