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18.104.22.168.3 When Generated The PACKET.indication primitive shall be passed from the service provider to the Packet
Service user at the receiving end to deliver a Packet.
22.214.171.124.4 Effect On Receipt The effect of receipt of the PACKET.indication primitive by the Packet Service user is
126.96.36.199.5 Additional Comments
The PACKET.indication primitive shall be used to deliver Packets to the Packet Service user
identified by the GVCID and Packet Version Number. Incomplete Packets may be delivered
3.4 VIRTUAL CHANNEL ACCESS (VCA) SERVICE 3.4.1 OVERVIEW OF VCA SERVICE
The Virtual Channel Access (VCA) Service provides transfer of a sequence of privately
formatted service data units of fixed length, along with status fields, across a space link. The
service is unidirectional, either asynchronous or periodic, and sequence-preserving. 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 3-6 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.
3.4.2 VCA SERVICE PARAMETERS
188.8.131.52 General The parameters used by the VCA Service primitives shall conform to the specifications
contained in subsections 184.108.40.206 through 220.127.116.11.
18.104.22.168 VCA_SDU NOTE – The VCA_SDU parameter is the service data unit transferred by the VCA
Service. For restrictions on the VCA_SDUs transferred by the VCA Service, see
22.214.171.124 VCA Status Fields The Packet Order Flag (1 bit) and Segment Length ID (2 bits) may be used to convey
information on the validity, sequence, or other status of the VCA_SDUs. Provision of this
field is mandatory; semantics are user-optional.
NOTE – The VCA Status Fields parameter consists of the Transfer Fram...
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This document was uploaded on 03/06/2014.
- Spring '14