Trouble in IMland

Stephen D. Williams
Tue, 15 Jan 2002 00:23:49 -0500 (EST)

In a sense, yes, IM is very old.  In fact, AOL always had IM, but it didn't
become useful and take off until BuddyList was released.  Regardless of the
fact that people often call it 'IM' and just assume the 'Presence'
(BuddyList, Roster, etc.) part, it's the Presence that makes the difference.

Some of the old systems did have a concept of presence of course, but
generally speaking they were missing some key components.  The primary
component is simply scalability and a critical mass of people to go with it.
   IRC may have a few 10's of thousands online, but it doesn't provide
notifications to users except by polling a subset generally and it's nothing
like the several 100K simultaneous that I handled and the 1Million+ that
AIM/AOL now handles.  (Probably 2-3 Million simultaneous these days at peak.)

While presence seems somewhat obvious, it was Barry Appelman that pulled
together some of the ideas that earlier attempts at presence were grasping
at (there were polling clients vamped onto AOL) and I was hired (as a
consultant!!! arghh...) to write BuddyList.

IRC, Zephyr, Compuserve CB Simulator (that I used in 1983 at 300 baud), and
others were limited in various ways, didn't have permanent IDs, didn't have
the full presence model, etc.  Zephyr was one of the more interesting
systems, but it had plenty of flaws.

What is the 'presence' model?  What model is implied by IM + Presence as
emodied by AIM, et al?

It is a model of:

A) Permanent logical endpoint addresses (Equivalent to Email addresses)
B) Publish/Subscribe model for updates to fundamental state (on, idle)
C) System-Wide authentication
D) Transparent, logical routing of realtime data from many to many usable as
both a streaming conversation or quick lightweight notes.
E) Multichannel, async communication.
F) Optimized client for updates, viewing, and rich text conversation.
G) Control over visibility, reachability.
H) Very low latency for any event or message in the system.
I) Pipelining, overlapped I/O, shared channels, and other optimizations that
allow sub-linear scaling.

I always used to draw a triangular diagram of email (async, bulk,
non-realtime, multi-channel), telephone (sync, narrow, realtime, single
channel), and IM/P (semi-sync, realtime, multi-channel, potentially bulk).

I think that IM/P has a far more rich communication model than HTTP.  I have
long pointed out that the killer application for IM/P systems would be to
add extensible XML payload routing and endpoint subaddressing and use it as
a global JMS-like application data routing application.  KnowNow-ish.

In fact there isn't any reason that you couldn't merge all the ideas in HTTP
with IM/P and JMS to create the ultimate flexible communications model.  Add
chunking, multiplexing, application level windowing, various kinds of
security and compression, and you have it all.

Once you realize all of that, it is quite annoying that there are such
strong movements to mold the world to the model of a near-term cell phone.
My handheld now runs Linux and Java, has 32-64MB ram, 1GB HD, 128MB flash,
and will shortly have 802.11B and CDPD.  And it has a real keyboard hidden
away.  (Sharp Zaurus 5000D).

> On Mon, 14 Jan 2002, Joseph S. Barrera III wrote:
> --]> And IM, what the fuck is that anyway..Its called IRfuckingC
> --]> people. IM is
> --]> nothing but hype to begin with.
> --]
> --]Wasn't I using Zephyr ten or fifteen years ago?
> --]
> Or you could have been getting Admin Chated, or even gone thru a few
> BBS Doors to get there.
> Remeber Genie back in 86 or so, they had the Icon Head chat roundtable
> thing, each person was a series of icons that changed by emotion code
> (happy, sad etc etc)
> Of course there was always just writting to a tty, wall em if you got
> em.
> Bottom line is this, The IM thing is a freaking fruity marketing wet
> dream with protocol whores falling over hypophiliacs to see who can
> pull the othres pud across the greatest distance and yet still get a
> little on em.
> Lets face it bub, multimedia chat is called TRIBES 2, so deal with the
> fact of being so far behind the curb 12 years old laugh at the whole IM
> thing.
> Fuck, if its gonna be that hyped you can be damn sure someone is gonna
> get a laser stuck up somewhere, and they have made it so.
> -tom

Stephen D. Williams
43392 Wayside Cir,Ashburn,VA 20147-4622 703-724-0118W 703-995-0407Fax Dec2001