Can the direct path not be the shortest distance?

2

I know this question sounds silly, but I've been reviewing distance vector tables from this site

Specifically this example where the direct path is longer than an indirect. Is this possible and if so, what are the conditions for this to occur?

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krikara

Posted 2013-03-05T17:20:39.680

Reputation: 329

Question was closed 2013-03-05T17:45:47.143

2Maybe a better question on the programmers or mathematics sites. – Brad Patton – 2013-03-05T17:23:29.910

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  • Speed of the network btw G-F 2) Avg load on interface where G meets F
    • < – SparKot – 2013-03-05T17:24:49.907

    1Edges are weighted, not necessarily by physical distance. – SparKot – 2013-03-05T17:26:09.973

    I was considering asking this on stackoverflow, but that site suggests code and this site explicitly said networking questions, so I figured this might be best. – krikara – 2013-03-05T17:26:13.230

    @SparKotॐ What exactly do the numbers represent if not physical distance? – krikara – 2013-03-05T17:28:21.467

    I think you are confusing a few things. the variable you are asking for, is built into the weights. determine how the weights are calculated, and you have your answer. you have presented a math problem as a networking problem, and the reality is based entirely on the characteristics of the network. – Frank Thomas – 2013-03-05T17:29:58.450

    @krikara Can you add more detail to the question that makes it a more real, solvable question, and less of a thought project? – killermist – 2013-03-05T17:39:10.477

    Answers

    6

    The path is not longer it is more costly. In the example you have posted, the edges are weighted. The table shows the cost of each path. Since the direct edge has a weight of 7, the direct path has a cost of 7. The indirect path has a cost of 4+1=5 so it is less costly even if it is shorter.

    I don't know what kind of network you are describing so I cannot know what these weights represent but that is why the cost is cheaper for the indirect path. The weights could, fir example, refer to network speeds. So, if F->D->G takes 5 seconds and F->G takes 7, the indirect path is faster because it goes through a faster network.

    terdon

    Posted 2013-03-05T17:20:39.680

    Reputation: 45 216

    Ahh okay. It seems kind of confusing how they label them as Distance tables when the edges aren't distances lol. – krikara – 2013-03-05T17:32:30.103

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