Saturday, August 1, 2009

Speeding Up Internet Access in Japan

I have a pretty fast fiber-optic connection here in Okinawa, Japan. Speed test with local Japanese servers have me anywhere from 11MB/s to 25MB/s. Unfortunately, everything I watch & download is from America, 7000 miles away: things can slow down significantly, especially with the default windows settings, which are for LAN connections.

Testing to USA servers was about 1.5MB/s down & 1.7MB/s up (BTW, this is the fasted upload speeds I've ever seen... posting pics and videos are incredibly fast, about 5-8x faster than what I had in the USA).

YouTube videos were stuttering quite a bit, even on low-res. YouTube has recently been rumored to 'throttle back' download speeds to overseas IP addresses. Fortunately, HULU SD were good, and the HD videos stuttered occasionally for buffering.

So, I did some "tweaking" of my TCP/IP stack and DNS. All diagnostic tools were from

Here's my tweaks:
MTU of 1454 (I have a PPPoE connection, and did the testing to make sure this was the max before packet errors surfaced, using MTUTEST.EXE)

TCP Receive Window: 260176
Windows scaling YES
Time Stamping NO
Selective Acks YES
Path MTU Discovery YES
Black Hole Detection NO
Max. Duplicate ACKs 2
TTL 64
(Testing and tweaking with DRTCP021.exe)

Increased max connection to 10 with M$ FixIt and/or Tweak-XP Pro IV

Then I opened up the router programming page, and made the DNS default to the OpenDNS servers: &

Now YouTube videos don't stutter any longer, and dslreport download speeds from USA servers have increased by double to 3.3MB/s down & 1.7 MB/s up.

Japan Server Speed Test (Tokyo):

Geek out,

keywords: tweak internet connection okinawa japan international TCP/IP MTU