Table of Contents:

Definition and Overview

1. The Current Status of IM

2. IM as an Integrated Communications Platform

3. Network-Based versus Device-Based Approaches

4. Presence Awareness

5. Security Issues

6. Standards and IM

7. Revenue Potentials

8. Conclusion

Self-Test

Glossary

PDF of this tutorial

An IM service can be either device-based or network-based. In a device-based system, the user information is located on the device used to access the system. The user downloads a client application to the device, most likely a computer. The user's list of contacts and other preferences specific to the user are saved on that computer. If the user accesses the system from multiple devices—a home computer and an office computer, for example—the same user information will have to be created on each device. If that information is changed—such as an address on the contact list—it will have to be manually changed on both computers. If the user accesses the system as a guest from a device that normally is not used, the user won't have access to personal contact lists or other personal information.

In a network-based system, the user information is stored on a network-based server, so users have access to the same customized services and information, no matter how they access the system. Client software will have to be loaded on devices used to access the service, but the same contact list, addresses, and other personal information will be available whenever users log into the system. If a change is made to information, that change will then affect all the devices that user uses. Users have the same information and the same services whether logging on from their home computers, office computers, or mobile phones. Because this information is located centrally, users also have the option of updating their own information for all other users. For example, if User A changes her e-mail address, she can make that change in the system. Then everyone who has User A on their contact list will automatically have their contact lists updated the next time they log into the system. User A won't have to send an e-mail to all her contacts asking them to change her address on their contact lists.

A network-based system is essential for offering true integrated communications across multiple device types, particularly for business users. These users are likely to access a messaging system from several computers, mobile phones, and PDAs, and they will not want to have to keep updating the information for each of these devices.