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Re: [tlug] Suggestions for poor FTTH performance

It appears to have been related to the MTU. There are various blog posts one can find online that suggest an MTU of 1454 when connecting to Flet's (from memory... I'm not at home right now so I can't double-check the value). I had the PPPoE MTU set to that value but the suggestion to put 1454 everywhere I could find (my router allows me to set MTUs of various sorts both on the PPPoE interface and the raw ethernet socket) seemed to do the trick. The key experiment was also suggested earlier in this thread -- connecting my desktop Windows machine to the ONU directly got me up to 90Mb+ so that told us it wasn't congestion or a problem with the fiber drop.

One confounding factor was that my router status wasn't reporting any fragmented or dropped packets and other sites seemed to work fine. Apparently SSL sites are sensitive to the MTU setting while others can limp along no matter what.

It's also remotely possible that dropping the connection entirely and restarting it did something -- but if I were a betting man, I'd go with the MTU setting as the root cause. I'm not going to set it back to verify that, though... I got in enough hot water at home breaking the connection to my wife's favorite news site ;-)...

On Fri, Apr 14, 2017 at 9:20 PM, Curt Sampson <> wrote:
On 2017-04-14 17:15 +0900 (Fri), Joe Larabell wrote:

> Thanks everyone for the suggestions. Just to follow up, I just got off the
> phone with a certain TLUG member who happens to work for AsahiNet and we
> walked through a few experiments and changed some router settings. I'm back
> in the land of the reasonably connected.

Can you give us a quick summary of the changes you made? I've been
having various issues with my Linux-based router and certain sites
that I've never gotten around to properly debugging; it's some weird
thing where they work from my Windows box but the same sites have
on-and-off massive packet lossage or similar when I access them from
my Linux laptop. (Currently I just make the problem go away by
switching to my other connection, which runs via a Linux box doing
NAT.) Maybe what you fixed will help me, too.

Curt Sampson         <>         +81 90 7737 2974

To iterate is human, to recurse divine.
    - L Peter Deutsch

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