TS Supplement (Includes RFC-1006 Support)

Changes in the Transport Layer When Using RFC-1006

Introduction to RFC-1006

107751 Tandem Computers Incorporated 1–21

TCP Service Primitives

TCP offers the following service primitives to the transport and network user, as

defined in RFC 793 and as shown in Table 1-5.

Table 1-5. Internet TCP Service Primitives

Events

Primitive Function

Connected Open succeeded (ACTIVE or PASSIVE).

Connect fails ACTIVE open failed.

Data ready Data can be read from the connection.

Errored Connection has an error and is now closed.

Closed An orderly disconnection has started.

Actions

Primitive Function

Listen on port PASSIVE open on the given port.

Open port ACTIVE open to the given port.

Read data Data is read from the connection.

Send data Data is sent on the connection.

Close The connection is closed.

Service Primitives Mapping

Between OSI Network

Service and TCP

RFC-1006 uses TCP's services to emulate OSI network service primitives. The

mapping of the network service primitives to the TCP service primitives as required

by the OSI transport protocol class 0 is shown in Table 1-6.

This table lists, for each OSI network service primitive, the related TCP primitives and

socket calls. The last column shows the equivalent Tandem NonStop file-system calls

that the TSP process would call when communicating over TLAM or X25AM, rather

than over TCP/IP.