Technical Reference: Communications, Volume 1

DL_DISCONNECT_REQ Primitive

Purpose

Requests that an active data link be disconnected.

Structure

The primitive consists of one M_PROTO message block, which contains the following structure:

typedef struct { ulong dl_primitive; ulong dl_reason; ulong dl_correlation; } dl_disconnect_req_t;

Description

The DL_DISCONNECT_REQ primitive requests the data link service (DLS) provider to disconnect an active data link connection or one that was in the process of activation. The DL_DISCONNECT_REQ primitive can be sent in response to a previously issued DL_CONNECT_IND or DL_CONNECT_REQ primitive. If an incoming DL_CONNECT_IND primitive is being refused, the correlation number associated with that connect indication must be supplied. The message indicates the reason for the disconnect.

Note

This primitive applies to connection mode.

Parameters

dl_primitive	Specifies the DL_DISCONNECT_REQ primitive.
dl_reason	Indicates one of the following reasons for the disconnect: DL_DISC_NORMAL_CONDITION Indicates normal release of a data link connection. DL_DISC_ABNORMAL_CONDITION Indicates abnormal release of a data link connection. DL_CONREJ_PERMANENT_COND Indicates a permanent condition caused the rejection of a connect request. DL_CONREJ_TRANSIENT_COND Indicates a transient condition caused the rejection of a connect request. DL_DISC_UNSPECIFIED Indicates the connection was closed for an unspecified reason.
dl_correlation	Specifies one of the following values: 0 Indicates either the disconnect request is releasing an established connection or is cancelling a previously sent DL_CONNECT_REQ primitive. >0 Specifies the correlation number that was contained in the DL_CONNECT_IND primitive being rejected. This value permits the DLS provider to associate the primitive with the proper DL_CONNECT_IND primitive when rejecting an incoming connection.

States

Valid

The primitive is valid in any of the following states:

DL_DATAXFER
DL_INCON_PENDING
DL_OUTCON_PENDING
DL_PROV_RESET_PENDING
DL_USER_RESET_PENDING

New

DL_DISCON11_PENDING

Acknowledgments

Successful	The DL_OK_ACK primitive is sent to the DLS user resulting in the DL_IDLE state.
Unsuccessful	The DL_ERROR_ACK primitive is returned, and the resulting state is unchanged.

Error Codes

DL_BADCORR	Indicates the correlation number specified in this primitive does not correspond to a pending connect indication.
DL_OUTSTATE	Indicates the primitive was issued from an invalid state.
DL_SYSERR	Indicates a system error occurred. The system error is indicated in the DL_ERROR_ACK primitive.

Related Information

The DL_CONNECT_IND primitive, DL_OK_ACK primitive, DL_ERROR_ACK primitive, DL_CONNECT_REQ primitive.