DLPI Programmer's Guide

Chapter 1 43
Introduction to DLPI
DLPI Services
Figure 1-25 Message Flow: DLS Provider-Invoked Connection Reset
Figure 1-26 illustrates the message flow for a reset invoked
simultaneously by one DLS user and the DLS provider.
Figure 1-26 Message Flow: Simultaneous DLS User & DLS Provider-Invoked
Connection Reset
Connectionless-mode Services
The connectionless-mode services enable a DLS user to transfer units of
data to peer DLS users without incurring the overhead of establishing
and releasing a connection. The connectionless service does not, however,
guarantee reliable delivery of data units between peer DLS users (e.g.
lack of flow control may cause buffer resource shortages that result in
data being discarded).
Once a stream has been initialized via the local management services, it
may be used to send and retrieve connectionless data units.
Connectionless Data Transfer
The connectionless data transfer service provides for the exchange of
user data (DLSDUs) in either direction or in both directions
simultaneously without having to establish a data link connection. Data
DL_RESET
indication
DL_RESET
indication
DL_OK
acknowledge
DL_RESET
response
DL_OK
acknowledge
DL_RESET
response
DL_RESET
request
DL_RESET
indication
DL_RESET
confirm
DL_RESET
response
DL_OK
acknowledge