Technical Reference: Communications, Volume 1

DL_CONNECT_REQ Primitive

Purpose

Requests that the data link service (DLS) provider establish a data link connection with a remote DLS user.

Structure

The primitive consists of one M_PROTO message block, which contains the following structure:
typedef struct { ulong dl_primitive; ulong dl_dest_addr_length; ulong dl_dest_addr_offset; ulong dl_qos_length; ulong dl_qos_offset; ulong dl_growth; } dl_connect_req_t;

The DL_CONNECT_REQ primitive requests that the DLS provider establish a data link connection with a remote DLS user. The request contains the data link service access point (DLSAP) address of the remote DLS user.

Note: This primitive applies to connection mode.

Parameters

dl_primitive	Specifies the DL_CONNECT_REQ primitive.
dl_dest_addr_length	Specifies the length of the DLSAP address that identifies the DLS user with whom a connection is to be established. If the called user is implemented using DLPI, this address is the full DLSAP address returned on the DL_BIND_ACK primitive.
dl_dest_addr_offset	Specifies where the destination DLSAP address begins. The value of this parameter is the offset from the beginning of the M_PROTO message block.
dl_qos_length	The DLS provider does not support any QOS parameter values. This value is set to 0.
dl_qos_offset	The DLS provider does not support any QOS parameter values. This value is set to 0.
dl_growth	Defines a growth field for future enhancements to this primitive. Its value must be set to 0.

States

Valid	The primitive is valid in the DL_IDLE state.
New	The resulting state is DL_OUTCON_PENDING.

Acknowledgments

There is no immediate response to the connect request. However, if the connect request is accepted by the called DLS user, the DL_CONNECT_CON primitive is sent to the calling DLS user, resulting in the DL_DATAXFER state.

If the connect request is rejected by the called DLS user, the called DLS user cannot be reached, or the DLS provider or called DLS user do not agree on the specified quality of service, a DL_DISCONNECT_IND primitive is sent to the calling DLS user, resulting in the DL_IDLE state.

If the request is erroneous, the DL_ERROR_ACK primitive is returned and the resulting state is unchanged.

Error Codes

DL_ACCESS	Indicates the DLS user does not have proper permission to use the requested DLSAP address.
DL_BADADDR	Indicates the DLSAP address information is invalid or is in an incorrect format.
DL_BADQOSPARAM	Indicates the QOS parameters contain invalid values.
DL_BADQOSTYPE	Indicates the QOS structure type is not supported by the DLS provider.
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.
DL_UNSUPPORTED	Indicates the DLS user has indicated QOS parameters, which are unsupported.

Implementation Specifics

This primitive is part of Base Operating System (BOS) Runtime.

Related Information

The DL_CONNECT_CONprimitive, DL_DISCONNECT_IND primitive, DL_ERROR_ACK primitive, DL_BIND_ACK primitive.