Telecommunications Protocols, Second Edition
The Big Picture of Telecommunications Networking - Today and Tomorrow
TABLE OF CONTENTS Telecommunications Protocols, Second Edition
Section 4.6: Internet Application Protocols
Section 4.6: Internet Application Protocols
We have discussed applications which use the services of both TCP and UDP. Now we will look at the most commonly used applications. These applications also use a protocol which is processed internally within hosts and is used for communications between the destination and originating hosts.
You will remember in our discussions about protocols that we described peer-to-peer protocols. These are protocols that communicate with the same protocol at the other end of a communication (whether it be a router or a host). Where the processing takes place depends on which layer the protocol resides on.
Internet applications are processed within hosts and are transparent to the network devices (routers and gateways). The network devices have no visibility to these and treat them as user data.
Section 4.6.1: TELNET
The TELNET protocol allows terminals or PCSs acting as terminals (terminal emulation) to communicate with remote hosts. The remote host may be a server running an application or a mainframe. Terminals are proprietary and are usually not compatible with one another. DEC terminals use a different terminal protocol than IBM terminals do. These differences must be resolved when connections are established with remote hosts. This is the task of TELNET. This protocol provides a means for all terminal types to communicate with remote hosts regardless of the terminal type. It allows the host to determine the characteristics of various terminals.
This is done using a series of commands to negotiate services the host can support. The...
Copyright The McGraw-Hill Companies, Inc. 2000 under license agreement with Books24x7
