For restrictions on the ocfsdu transferred by the

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Unformatted text preview: cates the Virtual Channel through which the OCF_SDU is to be transferred. NOTE – The GVCID parameter is the SAP address of the VC_OCF Service. 3.6.2.4 OCF_SDU Loss Flag The OCF_SDU Loss Flag is an optional parameter that may be used to notify the user at the receiving end of the VC_OCF Service that a sequence discontinuity has been detected and that one or more OCF_SDUs may have been lost. If implemented, the flag shall be derived by examining the Virtual Channel Frame Count in the Transfer Frames. 3.6.3 VC_OCF SERVICE PRIMITIVES 3.6.3.1 General The service primitives associated with the VC_OCF Service are: a) VC_OCF.request; b) VC_OCF.indication. 3.6.3.2 3.6.3.2.1 VC_OCF.request Function At the sending end, the VC_OCF Service user shall pass a VC_OCF.request primitive to the service provider to request that an OCF_SDU be transferred to the user at the receiving end through the specified Virtual Channel. CCSDS 132.0-B-1 Page 3-13 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL NOTE – The VC_OCF.request primitive is the service request primitive for the VC_OCF Service. 3.6.3.2.2 Semantics The VC_OCF.request primitive shall provide parameters as follows: VC_OCF.request 3.6.3.2.3 (OCF_SDU, GVCID) When Generated The VC_OCF.request primitive shall be passed to the service provider to request it to send the OCF_SDU. 3.6.3.2.4 Effect On Receipt Receipt of the VC_OCF.request primitive shall cause the service provider to transfer the OCF_SDU. 3.6.3.2.5 Additional Comments The VC_OCF.request primitive shall be used to transfer OCF_SDUs across the space link on the specified Virtual Channel. 3.6.3.3 VC_OCF.indication 3.6.3.3.1 Function At the sending end, the service provider shall pass a VC_OCF.indication to the VC_OCF Service user at the receiving end to deliver an OCF_SDU. NOTE – The VC_OCF.indication primitive is the service indication primitive for the VC_OCF Service. 3.6.3.3.2 Semantics The VC_OCF.indication primitive shall provide parameters as...
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This document was uploaded on 03/06/2014.

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