ISO 22663:2007 defines the Proximity-1 space link protocol data link layer (framing, media access, data services, and input-output sublayers). It specifies the protocol data units, framing, media access control, expedited and sequenced controlled data transfer, timing service, i/o control, as well as the procedures for establishing and terminating a session between a caller and responder. The coding and synchronization sublayer is defined in ISO 21459. The physical layer is defined in ISO 21460.

ISO 22663:2007 does not specify

• individual implementations or products;
• implementation of service interfaces within real systems;
• the methods or technologies required to perform the procedures; or
• the management activities required to configure and control the protocol.

The scope and field of application are furthermore detailed in subclause 1.3 of the enclosed CCSDS publication.