best effort has problems

Fri May 28 23:32:58 UTC 2004

On 28-mei-04, at 21:58, Gordon Cook wrote:

> I published a two month issue last weekend with the bottom line 
> conclusion that there can be no telecom recovery as long as the 
> industry relies solely on the best effort business model which I 
> believe is not economically sustainable.

I fail to see how the facts support such a conclusion. What's happening 
in the fiber business is free market economics 101. Sure, if people 
would magically start paying much more money in order to be guaranteed 
what they get anyway today, the people taking that money would be a lot 
happier. What else is new.

Still, such a "better than best effort" service has interesting 
technical consequences. A "better" service can't exist without a 
"worse" service. You can delay and drop packets a little with a 
lower-quality service, but not too much because TCP won't have it, 
leading to congestion collapse with a network full of retransmissions 
that never make it to the other end. So what we need is a new transport 
protocol or modifications to TCP that make it possible to use the 
available bandwidth even at high levels of congestion.