The MTU as shipped/configured by Three on my B535 was 1440.

Oh! Right!

How strange 🤔.

TimH30 said "The MTU as shipped/configured by Three on my B535 was 1440. "

Yes. mine was set to 1440 by default. I find an MTU of 1492 is the sweet spot. Then in Ethernet settings I change the DNS to 1.1.1.1 and 80.80.81.81.

This will resolve the website resolving problems for me mostly. Only when I'm maxing out the connection does the issue return, at this point I end up having to reboot the router to make it go away.

Three needs to add a "reboot my router every "xhrs" to its firmware on the B535, it'd solve a huge amount of manual resets for customers due to their "shonky network".

Edited by buggerlugs (Sat 25-Apr-20 08:23:27)

In reply to a post by buggerlugs:

Yes. mine was set to 1440 by default. I find an MTU of 1492 is the sweet spot.

As low as 1440 is odd, but 1492 is the number used on shared wired networks (such as BT wholesale) where the connection is shared with other customers and needs PPP around your data flow. The Ethernet (and also used on WiFi) default is 1500.

This is why you should leave the router at 1500 and change on the computer:

Your computer will send packets of 1500 bytes and they will hit the router, whereby the router itself has to hold on to them, cut them into 1492 or 1440 size units and send on.

Your computer has a lot more speed and capacity than your router, so because it is so busy cutting these packets of information into smaller sizes, it is throwing away speed.

If you change the MTU on your computer, then your router has to do nothing but forward the smaller packets to the network, something it can do very quickly.

They’ve done the B1 re-farm to 4G at my local mast in the last couple of days. What a difference, from under 1Mbps (0.08 in one recent test) to 20-30Mbps.

Unfortunately there is now some kind of routing problem on the backhaul. Lots of sites including this one just give server timeouts on 4G and won’t load at all. They load fine on 3G.

I am seeking advice from people who know a lot more than i do.
I was thinking about looking at EE for mobile BB,any thoughts,i am sick of three & there rubbish CS.

Edited by elvisarron (Sun 26-Apr-20 13:42:30)

In reply to a post by elvisarron:

I am seeking advice from people who know a lot more than i do.
I was thinking about looking at EE for mobile BB,any thoughts,i am sick of three & there rubbish CS.

My first piece of advice would be that you delete this post of yours and start a brand new thread to ask your question.

So far into such a long "complaints" thread many people will have stop reading it so won't see your post.

It,s ok.

In reply to a post by jchamier:

Your computer will send packets of 1500 bytes and they will hit the router, whereby the router itself has to hold on to them, cut them into 1492 or 1440 size units and send on.

Your computer has a lot more speed and capacity than your router, so because it is so busy cutting these packets of information into smaller sizes, it is throwing away speed.

If you change the MTU on your computer, then your router has to do nothing but forward the smaller packets to the network, something it can do very quickly.

That is why MTU discovery was invented, you shouldn't need to be changing MTUs on your computers.

In reply to a post by andynormancx:

That is why MTU discovery was invented, you shouldn't need to be changing MTUs on your computers.

Agreed, some VPNs do mess with it though.