User`s guide

151

TCP/IP Network Basics

TCP/IP Protocols

Sockets For TCP/IP protocol, when a packet is delivered to a specific IP address, it is

passed up to TCP or UDP and then to the appropriate host. This process

forms a funnel through the TCP/IP stack, called a

socket. A socket is

uniquely defined by the IP address, the end-to-end protocol (TCP or UDP),

and the port number.

This figure shows typical socket architecture. When a socket is first created,

it has an associated protocol but not an IP address or port number. A socket

must be

bound to a port number before it can receive messages from a

remote application.

Application Layer

Transport Layer

Internet Layer

UDP

TCP/IP Stack

2 65535. . . 1 2 65535. . .

Application

Application Application

TCP Sockets

UDP Sockets

Sockets bound

to ports

. . .

Sockets

TCP Ports

UDP Ports

TCP