DLPI Primitives

Connectionless-mode Service Primitives

DL_OUTSTATE

Primitive was issued from an invalid state.

DL_UNSUPPORTED

Requested priority not supplied by provider.

DL_UNITDATA_IND

Conveys one DLSDU from the DLS provider to the DLS user.

Format

The message consists of one M_PROTO message block containing the structure shown below, followed by one or more M_DATA blocks containing at least one byte of data. The amount of user data that may be transferred in a single DLSDU is limited. This limit is conveyed by the parameter dl_max_sdu in the DL_INFO_ACK primitive.

typedef struct

{

ulong

dl_primitive;

ulong

dl_dest_addr_length;

ulong

dl_dest_addr_offset;

ulong

dl_src_addr_length;

ulong

dl_src_addr_offset;

ulong

dl_group_address;

}dl_unitdata_ind_t;

Parameters

dl_primitive

DL_UNITDATA_IND

dl_dest_addr_length

length of the address of the DLSAP where this DL_UNITDATA_IND is intended to be delivered.

dl_dest_addr_offset

offset from the beginning of the M_PROTO message block where the destination DLSAP address begins.

dl_src_addr_length

length of the DLSAP address of the sending DLS user.

dl_src_addr_offset

88

Chapter 2