--- michael dolan <[EMAIL PROTECTED]> wrote:
> >I also wanted to point out that a server's
> proximity
> >to you (Baton Rouge area) does not mean it is
> faster.
> >  
> >
> Yeah (I live a block away from LSU and they were
> really bad), but isn't 
> this generally true?  When given a list of servers
> you can download a 
> file from, shouldn't you choose the one closest to
> you?  In a perfect 
> world, you would choose the fastest or least busy,
> but without that kind 
> of information...

Unfortunately, no. It really depends on which backbone
your ISP is on.

I'm glad you raised this question because the answer
involves a very interesting area of IT, namely network
backbones. I don't know a whole lot about it, but I do
know that ISP networks are not "meshed" or
equidistant. Your ISP could easily get its Internet
service or connection from far away as Dallas. So,
your connection to LSU could be taking a very long
route around the Internet to travel one block.

I guess the best place to start would be to introduce
the traceroute command. First, I do a 'whois lsu.edu'
command to find out the nameservers for LSU:


(blah, blah, blah,...)

Name Servers: 
   BIGDOG.LSU.EDU               130.39.244.8, 130.39.198.8
   OTC-DNS1.LSU.EDU     130.39.3.5,130.39.254.5
   OTC-DNS2.LSU.EDU     130.39.254.30,130.39.244.30

Next, I start a traceroute to bigdog.lsu.edu

[EMAIL PROTECTED] ~
$ tracert bigdog.lsu.edu

Tracing route to bigdog.lsu.edu [130.39.244.8]
over a maximum of 30 hops:

  1     3 ms     3 ms     3 ms  192.168.1.1
  2    14 ms    14 ms    14 ms 
adsl-pool-209-124-225-254.eatel.net [209.124.225
.254]
  3    17 ms    16 ms    15 ms  eatel-gw1.eatel.net
[209.124.193.254]
  4    15 ms    16 ms    15 ms  xdsl-gw2.eatel.net
[209.124.193.246]
  5    22 ms    22 ms    23 ms 
500.Serial5-11.GW8.HOU7.ALTER.NET [157.130.135.1
25]
  6    22 ms    24 ms    24 ms 
0.so-2-0-0.XL2.HOU7.ALTER.NET [152.63.101.166]
  7    30 ms    30 ms    29 ms 
0.so-1-0-0.XL2.DFW9.ALTER.NET [152.63.98.25]
  8    29 ms    31 ms    30 ms 
POS7-0.BR1.DFW9.ALTER.NET [152.63.98.133]
  9    30 ms    30 ms    30 ms  204.255.168.230
 10    30 ms    30 ms    30 ms 
dal-core-01.inet.qwest.net [205.171.25.45]
 11    38 ms    65 ms    50 ms 
iah-core-02.inet.qwest.net [205.171.8.126]
 12    37 ms    35 ms    36 ms 
iah-core-03.inet.qwest.net [205.171.31.42]
 13    51 ms    50 ms    51 ms 
atl-core-01.inet.qwest.net [205.171.8.146]
 14    51 ms    51 ms    50 ms 
atl-edge-17.inet.qwest.net [205.171.21.190]
 15     *        *        *     Request timed out.
 16     *        *        *     Request timed out.
 17     *        *        *     Request timed out.
 18     *        *        *     Request timed out.
 19     *        *        *     Request timed out.
 20     *        *        *     Request timed out.
 21     *        *        *     Request timed out.
 22     *        *        *     Request timed out.
 23     *

and I get tired of waiting for it to reach
bigdog.lsu.edu, so I killed the traceroute. Maybe
there's a network problem out there today?

Note that I am using Eatel in Gonzales, who apparently
uses Alternet out of Houston, who apparently has an
uplink in Dallas, who apparently gets service from
Qwest, who apparently has an uplink to someplace
called IAH and then from there to Atlanta, ...

So, you see my point. But even so, if you had really
big pipes between you and LSU, you wouldn't really
care, would you? ;) So, the time delay for network
requests are due to a couple of factors, among others:
number of hops between you and the target server, and
the bandwidth of the connections.

Now, I'm not a network engineer and I could be very
wrong about the above, but this is what I understand
to be the case from previous experience.

Could somebody more knowledgeble about Internet
networking chime in?

=====
John Hebert
Official BRLUG Linux Curmudgeon
Open Source Ankle Biter

__________________________________
Do you Yahoo!?
Get better spam protection with Yahoo! Mail.
http://antispam.yahoo.com/tools

Reply via email to