.. glossary::
BACnet
BACnet (Building Automation and Control Network) is the global data
communications standard for building automation and control networks.
It provides a vendor-independent networking solution to enable
interoperability among equipment and control devices for a wide range
of building automation applications. BACnet enables interoperability
by defining communications messages, formats and rules for exchanging
data, commands, and status information. BACnet provides the data
communications infrastructure for intelligent buildings and is
implemented in hundreds of thousands of buildings around the world.
The BACnet standard was developed and is continuously maintained by the
BACnet Committee, more formally known as SSPC 135 (a Standing Standards
Project Committee) of the American Society of Heating, Refrigerating
and Air-Conditioning Engineers (ASHRAE).
BACnet is an ISO standard (EN ISO 16484-5), a European standard (DIN EN
ISO 16484-5:2017-12) and a national standard in many countries.
BACnet device
Any device, real or virtual, that supports digital communication using
the BACnet protocol.
BACnet network
A network of BACnet devices that share the MAC or VMAC address space
under a particular BACnet network number.
BACnet internetwork
A set of two or more networks interconnected by BACnet routers. In a
BACnet internetwork interconnected by BACnet routers, there exists
exactly one message path between any two nodes.
BACnet Device
Any device, real or virtual, that supports digital communication using
the BACnet protocol.
ephemeral port
An ephemeral port is a communications endpoint (port) of a transport
layer protocol of the Internet protocol suite that is used for only a
short period of time for the duration of a communication session.
Such short-lived ports are allocated automatically within a predefined
range of port numbers by the IP stack software of a computer operating
system. `Wikipedia <https://en.wikipedia.org/wiki/Ephemeral_port>`_
upstream
Something going up a stack from a server to client.
downstream
Something going down a stack from a client to a server.
stack
A sequence of communication objects organized in a semi-linear sequence
from the application layer at the top to the physical networking layer(s)
at the bottom.
discoverable
Something that can be determined using a combination of BACnet objects,
properties and services. For example, discovering the network topology
by using Who-Is-Router-To-Network, or knowing what objects are defined
in a device by reading the *object-list* property.