On Wed, 15 Jul 2009, Randy Bush wrote:
The typical network architecture problem, what are the best (shortest latency, greatest bandwidth, etc) locations to connect to the every nation in the world? As you increase the number of locations, how do the choices change?
If you only had small (2 3 5 7 11) number of locations, where would they be?
And what data do you have to prove the choices are best?
it would help if you said how you measure 'best' or 'better'.
As I said in the original message, combination of minimizing latency (smallest RTT to the most IP endpoints) and maximizing bandwidth (largest number of bits per second successfully received at the most IP endpoints in the smallest amount of time) from the locations identified as best. On Wed, 15 Jul 2009, Jareon Masser wrote:
Depends completely on what the data is and why you want to send them from A to B and if A and B are inside your network or not etc etc etc etc.
As I said in the original message, every nation in the world. Or more specifically the largest number of IP endpoints reachable in the most nations from the locations chosen. A = the few locations you pick B = every other IP endpoint reachable from those locations If every point B in the world is inside your network, awesome. But highly unlikely. More than likely to maximize reachability, minimize latency, the highest goodput, and most availability will require some combination starting locations and ISPs. The data is IP applications in use now and in the future. Why do you want to send them from A to B, because you never know what is going to happen in the world and you want to be prepared for any point B to have the best chance of being able to effectively communicate with the chosen points A. On Wed, 15 Jul 2009, Bill Woodcock wrote:
However, if one wanted the beginnings of an answer, without nailing down any of the specifics, merely looking at the quantity of routes available at each IXP would let you know, on average, how many paths there were on offer to each destination.
The starting locations aren't necessarily IXPs. They could be ISPs with full transit connections at the chosen locations. But the goal includes maximizing reachability to the world, which probably means a full transit connection near many other ISPs would do better than a full transit connection far away from many other ISPs.
As others have noted, this is a many-variables sort of problem, and to answer it well requires nailing down a few of those variables
True, optimization and constraints solving is easier with fewer variables. There are also researchers that seem to spend lots of time measuring the Internet and collecting data for all sorts of reasons. When creating graphs of the Internet, one of the basic problems every mapper has to solve is deciding where are the "centers" of the map.