ADSL Line speed (Congestion)

[slabs]

Something that has puzzled me for a while is that when a ADSL line is congested (many people in neghbourhood using it at the same time), the speed drops.

But some are on a 2meg line, others on 4meg, 10meg, etc.

My question is: Do all get limited in the same way or are users at different line speeds affected differently?

 

[Dr Who]

I can tell you from experience I had a 4mb connection and it ran at 2mb due to congestion. I then downgraded and it was completely useless. I then ended up upgrading to 10mb so that I just had a usable 5mb-6mb. The system beat me in the end.