Shortest path to the world
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?
Sean Donelan 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?
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. aka ETOOMANYVARIABLES.
And what data do you have to prove the choices are best?
Depends of course on what you want to 'prove' But things that come into mind are possibly: - Netflow/sFlow and other such data - latency tests (simple pings from A to B to global services that check latency, eg RIPE TTM boxes) - Cost for circuits - and lots lots more. It all depends, thus also how you combine the above ;) Greets, Jeroen
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'. if you had a completely free hand, what experiment would you set up to measure this space? randy
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.
In a message written on Wed, Jul 15, 2009 at 10:39:05PM -0400, Sean Donelan wrote:
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.
I will assert that for all the small numbers (N < 5) the answers are non-overlapping sets. That is, not that these are the acual sites, N = 1 may be New York, N = 2 may be Amsterdam and LA, N = 3 may be Hong Kong, Chicago, Frankfurt, and so on.
More than likely to maximize reachability, minimize latency, the highest goodput, and most availability will require some combination starting locations and ISPs.
Reachability, latency, and goodput can not be all minimized at the same time. There are more than one way to create a synthetic metric combining the three, so it's quite unclear how to answer your question.
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.
95% of the mapping efforts look only at reachability, and then from incomplete data. Another 4% look at it from latency. 1% look at it from goodput. I have never seen a data set that related two, much less all three in any meaningful way. Quite frankly, your question reminds me a bit of the geography question "where is the center of the US". http://en.wikipedia.org/wiki/Geographic_center_of_the_contiguous_United_Stat... While nifty trivia, it acutally has no useful value for well, anything. If it did, there would be more there than a small monument. If you're going to deploy something, in addition to the criteria you have listed you will have to consider cost and availability of colo, transit, exchange ports, equipment, your businesses costs and time in doing business in multiple jurisdictions, getting people to these locations to set stuff up, cost and availability of bandwidth between sites, management overhead of what you're going to deploy, and so on. One last wrench in your works. It depends on how much traffic you want to do. If you want to move 50Mbps total, the answer is entirely different than if you want to move 500Gbps. Goodput holds until links fill, and which point it falls off. Plenty of video sites have great goodput from their set of locations until a flashmob (say, Michael Jackson) comes along and then the goodput from the same set of sites crashes and burns. So, you have a question that probably can't be answered, but if it could the answer doesn't matter, and even if it did, the Internet is dynamic so it will all be different tomorrow. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/
On Wed, 15 Jul 2009, Leo Bicknell wrote:
Quite frankly, your question reminds me a bit of the geography question "where is the center of the US". http://en.wikipedia.org/wiki/Geographic_center_of_the_contiguous_United_Stat... While nifty trivia, it acutally has no useful value for well, anything. If it did, there would be more there than a small monument.
Unless you were Federal Express, and wanted to understand where the "center" of your service area was to help pick better airport hub locations. Add in some offsets for time zones, weather, and even more complexity and your hub ends up in Memphis. Optimal can sometimes mean its good enough, even the momument at the center of the United States isn't actually located at the precise center. http://ardent.mit.edu/airports/ASP_exercises/ASP%20matl%20for%20posting%2020... Operations research is filled with people trying to figure out the optimal number of hubs, hub locations, routes between them for all sorts of stuff. So where are the operations research people studying the Internet?
In a message written on Thu, Jul 16, 2009 at 02:07:12AM -0400, Sean Donelan wrote:
Unless you were Federal Express, and wanted to understand where the "center" of your service area was to help pick better airport hub locations. Add in some offsets for time zones, weather, and even more complexity and your hub ends up in Memphis. Optimal can sometimes mean its good enough, even the momument at the center of the United States isn't actually located at the precise center.
The center of FedEx's world has nothing to do with geography, it has to do with flight times. JFK's prennial 1 hour delays make that flight an hour longer, even though it is no further away. Also, if I had 20 flights to the east coast, and 1 flight to the west coast, I may well "shift my center" east choosing to burn more fuel and time on one flight to save fuel on 20. Oh yeah, and then there are the other hubs in Indianapolis, Fort Worth, Oakland, Newark, Anchorage, Paris, Guangzhou, Toronto and Miami. Guess Memphis isn't the best, all by itself. Anchorage you might say? That's odd. Well, turns out a fully loaded freight aircraft have trouble making it from many Asian countries to the US on one tank of fuel. If you have to stop to refuel you might as well sort some packages while your waiting for it to pump into the plane.
Operations research is filled with people trying to figure out the optimal number of hubs, hub locations, routes between them for all sorts of stuff.
So where are the operations research people studying the Internet?
At every ISP and content provider out there. The answer is different for every company. FedEx and UPS don't have the same hubs, because they don't serve the same customer base. Akamai, NTT, and DTAG all have different points of presense based on their customer bases. Each one has the "optimal" network for their customer base. Your question is akin to tell me the best car, house, boat, airline, ISP, operating system. Magazines love to crown the king, but we all know making the right choice has orders of magnitude more to do with your specific situation than it does with the product or service in the abstract. -- Leo Bicknell - bicknell@ufp.org - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/
On Wed, 15 Jul 2009 22:03:56 +0900, Randy Bush said:
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?
And what data do you have to prove the choices are best?
it would help if you said how you measure 'best' or 'better'.
Given that it's Sean asking, I have to conclude he's either dropping a very interesting thought experiment on us, or he's just trolled us, with a long list of well-known names replying. Quite possibly both at once. Well played, Sean. ;)
On Jul 15, 2009, at 5:07 AM, Sean Donelan 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?
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 by combining the statistical output of netflow from your border routers with knowledge of the routing tables available at each potential IXP gleaned from looking-glasses at those IXes. ( http://pch.net/routing-tables being the source of such data that I can offer; the RIPE RIS program does the same thing with a partially-overlapping and partially-unique dataset; the union of the two gives the most complete available picture.) 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. In all likelihood, different paths available to a given destination will be of different lengths. The more paths available to each destination, the greater the likelihood that one path will be shorter than others or, more to the point, shorter than your current shortest. ( https://prefix.pch.net/applications/ixpdir/?show_active_only=0&sort=prefixes&order=desc or just go to http://pch.net/ixpdir and sort by prefixes. Only a router with a full mesh of peers at an IXP could actually show _all_ of the available routes at an IXP, so nearly all views of this sort will be substantially incomplete; take with a healthy dose of skepticism, and please let me know if you find more complete public sources.) -Bill
Sean Donelan 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?
Just a quick wikipedia and google search would provide you the answers to that: http://en.wikipedia.org/wiki/List_of_countries_by_number_of_Internet_users http://en.wikipedia.org/wiki/List_of_Internet_exchange_points_by_size http://www.internetworldstats.com/stats.htm http://www.internetworldstats.com/stats1.htm http://www.internetworldstats.com/stats4.htm etc... have fun with all that data! Kind regards, Michiel Klaver IT Professional
On Thu, Jul 16, 2009 at 4:14 AM, Michiel Klaver <michiel@klaver.it> wrote:
Sean Donelan 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?
Just a quick wikipedia and google search would provide you the answers to that:
http://en.wikipedia.org/wiki/List_of_countries_by_number_of_Internet_users
it's possibly useful to take into consideration _overall population since broadband penetration is likely to grow in a population vs. remain stagnant or decrease. That may suggest that the largest submarine cable landing points agggregators (Telehouse, 111 8th, etc. NOTA MIA) would be optimal for shortest reach to multitudes of networks and large amounts of capacity and give you "reach" as well as decent performance. My picks were NOTA facing the Americans, 118th/60 Hudson US, and Telehouse London for Europe. I'm not suggesting that an IX is required. Would be nice to keep costs down if that's also part of the objective, but not required. There's a project that is mapping datacenters onto Google Earth globally and if I could recall the URL I would suggest that a visualization of these answers may be interesting. Best Regards, Martin -- Martin Hannigan martin@theicelandguy.com p: +16178216079 Power, Network, and Costs Consulting for Iceland Data Centers and Occupants
participants (8)
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Bill Woodcock -
Jeroen Massar -
Leo Bicknell -
Martin Hannigan -
Michiel Klaver -
Randy Bush -
Sean Donelan -
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