To an ESROP user the ESROP Services offer the means to perform an Operation with another ESROP-User for the purpose of exchanging ESROS Data Units (DU). More than one Operation may be in progress simultaneously between the same pair of ESROP-Users.
ESROP is designed to be independent of the environment to which it will be ported.
ESROP appears to its user as a link module with four defined interfaces. The ESROP module's interfaces are shown Figure 2.1.
The ESROP upper interface is a series of function calls (primitives). Each function call accepts a group of arguments (parameters).
The Neda ESROP upper interface provides the ESROP-User with primitives which match the definitions of ESROS services [1]. Each function call is non-blocking and asynchronous.
ESROP requests and responses, collectively referred to as ESROP action primitives, are function calls to the ESROP software module. ESROP action primitives are invoked by the ESROP-User. The code for ESROP action primitives is provided by the ESROP software module.
ESROP indications and confirmations, collectively referred to as ESROP event primitives, are function calls to the ESROP-User module. ESROP event primitives are invoked by the ESROP software module. The code for ESROP event primitives is expected to be provided by the ESROP-User.
Section 2.4 describes in detail the ESROP upper interface primitives and their parameters.
The lower interface of the ESROP software module matches the upper interface of the Transport software module.
The ESROP lower interface is a series of function calls (primitives). Each function call accepts a group of arguments (parameters).
Neda ESROP lower interface primitives match the ESRO Service definitions [1]. Lower interface function calls are non-blocking and asynchronous.
Transport requests and responses, collectively referred to as Transport action primitives, are function calls to the Transport software module. Transport action primitives are invoked by the ESROP software module. The code for Transport action primitives is expected to be in the Transport software module.
Transport indications and confirmations, collectively referred to as Transport event primitives, are function calls to the ESROP software module. Transport event primitives are invoked by the Transport software module. The code for Transport event primitives is provided in the ESROP software module.
ESROP relies on the availability of a group of facilities for data unit and timer manipulation. A common high-level interface for these facilities is used by the ESROP module. This interface is defined in Open C Platform document, [1] and reviewed later.
A set of counters is locally maintained by the ESROP software module. These counters, which may be used for Network Management, are described later.
