How is 300GBPS a lot? If we take London which has 8million and say roughly half of them are on the internet (4million). Wouldn't that mean that if everyone was using 78kbps we would reach 300 gbps(roughly)?
I just don't understand how a tier1 or internet exchange router can only handle 100gbps. That seems extremely low to me considering I have like 1mbps for just my house?
Pretty much, 100Gbps is about 100 thousand times your internet connection. So, a single 100Gbps line could handle 100 thousand people like you requesting a 1mb file at the EXACT same moment. Spread that out by even a few seconds and that router can handle way more people than that 100 thousand.
This is a GROSS oversimplification, but the idea stands.
This diagram from wikipedia shows some of the sorts of alternate routes that might be used: http://en.wikipedia.org/wiki/File:Internet_Connectivity_Dist...
As an aside: does anyone know of a good resource that gives an example of the rough percentage of traffic that would be handled in each of the various ways?