Course: CS125
Name: Josh Smallman
Abstract Due Date: 1-19-00
Date: 1-19-00
Article Title: Instant Messaging / Presence Protocol Requirements
Journal Ref: http://www.ietf.org/internet-drafts/draft-ietf-impp-reqts-04.txt
Formatter: html



This internet draft discusses the necessary aspects of an Instant Messaging and Presence Protocal. Currently, there are lots of different messaging and presence services available on the Internet, such as Mirabilis' ICQ, America Online's "Instant Messanger" (AIM), and Peoplelink. This working group is attempting to define a standard protocal with which any service of this type would be able to communicate with any other one. To do this they must create a protocal with offers all the features necessary for such services.

Presence is defined in the paper as "a means for finding, retrieving, and subscribing to changes in the presence information (e.g. "online" or "offline") of other users." Instant messaging is defined as "a means for sending small, simple messages that are delivered immediately to online users."

One aspect of the proposed protocal that I was pleased to discover was the concern for mobile IP wireless access devices. The abstract claims (correctly, I believe) that it's is not reasonable to assume that separate protocals will be available for the wireless portions of the Internet. The Working Group therefore took that into consideration when creating the protocal. Some of the concerns included high latency, low bandwidth, intermittent connectivity, modest computing power, battery constraints, small displays, and to be reasonable efficient for small payloads (since the messages sent are relatively small in length).

Other concerns that the draft considers are the effects of large scale usage of the protocal. For example, the protocal must meet its functional and performance requirements even when there are millions of entities within a single domain, millions of domains within a single namespace, etc. This is obviously a wise decision, since ICQ has over 15 million users (that's a really old number too- I don't know how big it currently is!)

Also dealt with in the draft is access control and security. The person (called a Principal controlling a Presentity in the article) must be able to control who can see their presence information, what information they can actually see, and whether they can modify that information. It also controls who can send instant messages to or read instant messages from a message inbox (called an Instant Inbox).

The protocal must also provide security for the messages, such as a way to ensure that a recieved message has not been corrupted, altered, or "recorded and played back by an adversary." However, the draft specifies that while the protocal must provide these services, it must not require that all clients use them at all times.

While instant messaging services have grown immensely in the past few years, I believe that they will become even more invaluable as more wireless devices are available to the general public. I currently use a wireless 2-way email pager that sends and recieves email using a push service (rather than polling). While this takes care of the instant messaging part, a presence service would be quite useful in making the service more complete.