Distech ECYPSE - Internet Protocol Suite Overview

Internet Protocol Suite Fundamentals
ECLYPSE User Guide 17
Internet Protocol Suite Overview
Internet Protocol (IP) is part of a multi-layered suite that together enables data
communication. The following descriptions are an overview of the IP suite protocol layers as
used by IP devices:
 Physical layer (bits): This is the physical and device-to-device electrical connection layer
otherwise known as Ethernet. This layer defines:
 The requirements for the physical connection between devices (the signal medium).
For example, RJ-45 connectors (attached per TIA/EIA-568-A,), using Cat 5e data
cable. The maximum cable length between devices is 328 ft. (100 m) at 100 MB/s
data rate.
 The electrical signal requirements for data packet transport.
 The data packet structure including data payload and the source and destination
device’s MAC addresses.
In the case of Wi-Fi connected devices, the link layer is the air interface defined by the
Wi-Fi standard, such as radio frequencies, data rates, authentication, data channel
encryption, and so on.
 Data Link layer: This layer implements the ability for two devices to exchange data with
each other.
 Network layer: This layer implements the ability to connect multiple distinct networks with
each other. It provides the internetworking methods that allow data packets to travel
from the source device to a destination device across network boundaries, such as a
router through the use of an IP address. See About Routers, Switches, and Hubs.
 Transport Layer (segments): This layer provides end-to-end communication data stream
connection between two or more devices through a variety of protocols. However it is
the Transmission Control Protocol (TCP), the most commonly used internet transport
protocol that is used by Distech Controls IP controllers to communicate with each other.
TCP creates a connection-oriented channel between two applications; that is to say the
data stream is error-checked, is sorted into the correct sequence (missing data packets
are re-transmitted) and this data stream has a port number for addressing a specific
application at the destination host computer.
 Session layer (data): This layer implements the protocol to open, close, and manage a
session between applications such that a dialog can occur.
 Presentation layer: This layer implements the display of media such as images and
graphics.
 Applications layer: This layer implements the process-to-process communications
protocol that includes among other services the BACnet/IP protocol, programming,
debugging, WWW, and so on.
All of the above IP suite protocol layers must be fully functional for any two devices or
controllers to communicate with each other. For more detailed information about the IP suite
protocol layers, see http://www.wikipedia.org/.