UDP vs. TCP distribution [was: Re: [e2e] Can feedback be generated...]

[Sean Doran]

Mmmm, socio-psychology meets networking.  Always fun, never understood fully. :)

| It would be useful to know the absolute highest delays that gamers can 
| tolerate.

Surely this will be somewhat application-dependent?

However, there's probably some literature here and there about
human reflexes and how fast one needs a result back from a "twitch"
in order to feel reasonably interactive.   Probably very little
of that will focus on network impact.

| >FWIW, network games are fascinating examples of interactive applications.

They're also fun.  I've never been big into shoot-em-up games,
since building the Internet is faster and harder, but some friends
had me over to play Unreal Tournament with their clan the other week,
and my eyes were opened a bit.  UT in any event was more sensitive
to loss and "drop outs" than to stable delay -- for me, anyway, choppy
updates and missed action was more important and harder to compensate
for than aiming ahead along the direction the target is seen to be moving.

| I agree. I'm particularly interested in the multiuser aspects - for example, 
| as you state, there are dynamics which may force users with similar network 
| characteristics to congregate together.

It turns out that LAN parties are pretty common: people drive across
Europe to gather together around a hub or small switch, matching up
as teams in a series of competitions within a broader league.  

The social aspect, it turns out, is as important as the locality.
By analogy, although a good SLA can be gotten from a high-quality
Chinese Restaurant's delivery service, 15 people eating the same
stuff and communicating via a telephone bridge or IRC or whatever
is not as much fun as the same 15 people together in the restuarant,
even if the food is no better prepared or presented, and arrives
at the table no more quickly.

In the Internet space, we all know that there is a significant
value in the social aspect of IETF meetings, despite the formalization
of the mailing lists as being the places where real work happens.

| Alas, games seem to have been neglected by the networking
| research community, but hopefully that is changing.

Heh - well, they're sure popular among operators, at least those
on the operations front, as far as I can tell.  Perhaps that is
a reflection of a dichotomy between people who are reactive & practical
versus people who like to plan in advance and understand the theory
behind things.

	Sean.