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Re: [tlug] Tokyo ISP Throttling? Why does my internet speed increase so much by setting up a proxy?

Raymond Wan writes:

 > >>From home, 9 hops is required.  It spends some time around Hong Kong a
 > bit, staying within servers belonging to the ISP.  Then it jumps
 > directly to Oregon and then to California.
 > Meanwhile, from work, 14 hops is required.  It bounces around Hong
 > Kong a bit longer, including spending some time on a "HK University
 > Backbone" -- I presume this is a shared backbone for all universities
 > in the city.  Then it goes off to the UK, and then enters the USA.

It's just like a local train, stops are basically more costly than
distance.  The long distances are covered basically at the speed of
light, maybe as low as 50ms certainly less than 100ms, and I bet
you're looking at ping times in the 400-600ms range.

 > The ping times are longer from home (I think that is the round-trip
 > time in ms?),


 > but maybe the different path and more hops plays a bigger part in
 > download times?

Path as such doesn't matter (the Russian Mafia isn't siphoning off
packets to sell to Columbian druglords or anything like that), and a
factor of 2 in distance is probably a secondary consideration in any
case.  More hops matters for two reasons, both probabilistic.  First,
every hop is a chance to encounter congestion and have packets
dropped.  Second, every hop is a chance to encounter a configuration
problem, and perhaps have packets fragmented.  More fragments (which
at the IP level are just packets that can be dropped) means a higher
probability of a corrupt packet that must be retransmitted, and that
slows things down, even in a streaming protocol.

The other thing is that I wouldn't be surprised if ICMP (Internet
Control Message Protocol) packets get a higher priority and faster
relay in many cases than TCP packets.

 > The university is suppose to upgrade its network "over the next few
 > years" so maybe we an see some improvement...but I don't think
 > there's anything we can do to alter the path it takes to the USA...

The university could buy connectivity from your home ISP. :-)

Or you could borrow the connectivity you already have.  One thing I do
a lot is use SSH tunnels from home.[1]  It's possible to use these
tunnels (or specialized applications) to set up a personal VPN.  Then
you can (quite safely) reach your box at home from work without
opening it up to all kinds of evil.


[1]  Especially the X protocol tunnel with a remote browser, because
many of the University services I use want a local endpoint or they
fail authentication.  If you use ssh with the -X flag set, when you
start an X application on the  remote host, it is automatically
tunneled over your SSH connection to your local workstation's X
server.  It's perceptibly slow, but often usable, especially when I'm
hiding from somebody at school! ;-)

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