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Ping help

  1. Nov 26, 2012 #1
    I am just playing with the Ping command and would like some help understanding it.

    I used Ping on Google and 4 Packets of 32 Bytes of Data went out and came back.
    And the TTL for eatch Packet was like this

    TTL = 30 ms
    TTL = 31 ms
    TTL = 30 ms
    TTL = 29 ms

    Now I know that this is how long each Packet took to go and come back.
    And it should stay under 50 ms. and anything over something is wrong.

    But how do ppeople findout how far away the server is from just Pinging it?

    I know 1,000 ms = 1 SEC. so if my Pakets took 31 ms to get to and come back from google does this mean the server is how many MIN. away it is?
  2. jcsd
  3. Nov 26, 2012 #2


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    Gold Member

    I doubt there is any strict correlation between the ping number and the distance to the server. It will depend on how many nodes the signal goes through to get there and back and how fast they are.

    Also, "should stay under 50ms" is a decent rule of thumb, BUT ... there are many sites that are run off of shared servers, sometimes heavily shared servers, that will rarely give you better than, say, 100ms response time, so it is NOT just a matter of the signal getting there and back, there is also the processing time of the server and that can be slowed down by its load, having nothing to do with the rest of the signal transmission time.
  4. Nov 26, 2012 #3
    Thanks for getting back to me.

    But I do want to know google gave me a TTL of 30ms 31ms 3ms 29ms they are all very very low.

    so this tells me they all came back fast and had no prablems.

    Is there any way to ajust the Size of each Packet from 32 Bytes to whatever you want?
  5. Nov 26, 2012 #4
    Yeah, you'd have to make some crazy assumptions to get an idea of how far away the server is. Just for fun though, let's assume that the line is ideal and the signal travels at the speed of light, and that the server is perfect with no interuptions and doesn't have to go through clusters etc. So from 30ms we can get that the server you have pinged is about 4500 km away, which is 1/9 of the earth's circumference or like from one side of the U.S to the other. Being an engineer, I would call this a conservative estimate :) or the maximum case. Completely pointless, but interesting.

    Btw, 30ms is damm good, from Australia we get 100ms from most servers not in our country.
    Last edited: Nov 26, 2012
  6. Nov 27, 2012 #5
    Have a look at the Tracert cmd, it may help you understand where the ping is actually coming from, the time it takes to hop over all the other connections to google or any server in general and then back again. this is why it is generally impossible to determine how far a server is from your current location, not to mention all networks do not just run in straight lines in terms of distance. you could also look into routing as well as its quite interesting where you get pings from depending on switch configuration and what route your computer takes to collect the information.
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