Latency is the cause; bandwidth is the solution

Actually, what Herman Wagter of Amsterdam's Citynet said at F2C 2009 was:  latency is the cause, bandwidth is the effect.  But his explanation matched my title above.

If you are attempting to interact with other people, whether by VoIP or just playing cards together (with video) you need less than 200 milliseconds of end-to-end delay.  If it's playing cards together, with video, and you need to exchange 500 Kbps in less than 200 ms, you need a 100 Mbps pipe!

It's latency that drives the need for high bandwidth.  Most people won't fill that pipe most of the time, but they need the pipe to guarentee that what they do send gets through rapidly.

Comments

[Allen]

Doesnt full minimally compressed HD TV need at most 8Mb/s (or was it 16 I dont recall)? 500Kbit in 200ms may not be realistic... yet.

But even then, I'm not sure that more bandwidth is going to help - unless you're talking about a network that is so congested that you are seeing 200ms of queuing delay (and god awful jitter and packet loss as well).

But in properly provisioned networks a delay of 200ms is going to be mostly propagation delay and (in best Scotty from Star Trek accent) "You canna' change the laws of physics capt'n!" ;-)

[brough]

Allen (and the others who questioned via Twitter and email), Sorry to be sloppy. My only excuse, is the rush of being in the room with multiple things going on at once.
A better post is here:
http://blogs.dialogic.com/2009/04/more-bandwidth-less-delay-less-latency.html