NBN ISO 18440:2021

This Recommended Standard defines a protocol for transfer of SLE PDUs between an SLE
user and an SLE provider system in terms of:
a) the procedures used to establish and release associations;
b) the messages exchanged on an established association;
c) the procedures used to monitor the status of data communication connections; and
d) the methods used to ensure that data are converted between different formats and
representations on different platforms.
It does not specify:
a) individual designs, implementations, or products;
b) the configuration of the data communications infrastructure, including configuration
of the TCP and IP protocols;
c) the means by which addresses (IP addresses and TCP port numbers) are agreed,
assigned, and communicated.
This Recommended Standard responds to the requirements imposed by the Recommended
Standards for SLE transfer services that were available when this Recommended Standard
was released. The protocol specified in this Recommended Standard conforms to the
requirements on data communication services set forth in those Recommended Standards.