TABLE OF CONTENTS The protocols in the IEEE 802.3 Ethernet standard enable the computers in a local network to exchange messages with each other. In practice, most Ethernet networks also use Internet protocols such as TCP or UDP and IP. These provide defined and well-supported methods for accomplishing common tasks such as flow control and flexible addressing and routing of messages.
Messages that travel on the Internet must use IP. And because TCP and UDP are designed to work along with IP, local communications that use TCP or UDP also use IP, even if they wouldn t otherwise require it.
This chapter begins with a guide to connecting embedded systems to the Internet. Following this is an introduction to the Internet Protocol, including when and how embedded systems can use it in local and Internet communications.
To communicate over the Internet, a computer must have three things: an IP address that identifies the computer on the Internet, the ability to send and receive IP datagrams, and a connection to a router that can access the Internet.
An Internet Service Provider (ISP) can provide one or more IP addresses and a connection to a router that can communicate over the Internet. Customers use a variety of ways to connect to ISPs. A high-volume user, including the networks at some large businesses, government offices, and schools, may have a dedicated, high-speed connection to an ISP. If your network is located at a facility that has this type of access,...
