scope:

This Recommendation I International Standard defines in an abstract way the externally visible service provided by the OSI Transport Layer in terms of:

a)the primitive actions and events of the service;

b) the parameter data associated with each primitive action and event;

c) the relationship between, and the valid sequences of, these actions and events.

The service defined in this Recommendation I International Standard is that which is provided by ali OS1 Transport Protocols (in conjunction with the Network Service) and which may be used by any OS1 Session Protocol.

This Recommendation I International Standard does not specify individual implementations or products, nor does it constrain the implementation of entities and interfaces within a system. Conformance of equipment to this Recornmendation I International Standard is achieved by conformance to the protocols specified to fulfil the Transport Service defined in this Recommendation I International Standard.