scope:

This Recommended Practice defines extensions to the SLE API in terms of:

a) the CLTU-specific functionality provided by API components;

b) the CLTU-specific interfaces provided by API components; and

c) the externally visible behavior associated with the CLTU interfaces exported by the components.

It does not specify

a) individual implementations or products;

b) the internal design of the components; and

c) the technology used for communications.

This Recommended Practice defines only interfaces and behavior that must be provided by implementations supporting the forward CLTU service in addition to the specification in reference [5].

PURPOSE

The Recommended Practice Space Link Extension-Application Program Interface for Transfer Services-Core Specification (reference [5]) specifies a C++ API for CCSDS Space Link Extension Transfer Services.

The API is intended for use by application programs implementing SLE transfer services. Reference [5] defines the architecture of the API and the functionality on a generic level, which is independent of specific SLE services and communication technologies. It is thus necessary to add service type-specific specifications in supplemental Recommended Practices. The purpose of this document is to specify extensions to the API needed for support of the Command Link Transmission Unit (CLTU) service defined in reference [4].