Finding pages loading slowly? Try this MTU tweak

[fredwestie]

It's from the mouths of Tier3 support (yes - they exist and are brilliant) and it solved my page loading issues in a stroke.

1. Login to router status page.
2. Click on wan setup (this is on the left hand side of the page).
3. Change MTU size from 1500 to 1458, once you change the size click on apply.
4. Open a second internet explorer session and go www.bbc.co.uk and click on different news stories, check to see if the speed of the stories has speeded up.
5. If 1458 has not worked that well, try 1440. You may have to try as far down as 1410 in the MTU size to get the best setting. Each time you change the MTU check the speed that the pages open up at.
6. You may initially need to restart your PC and switch the sky broadband box off. If you reset the router you will change the MTU size so I'd advise you just to switch the power off on the box.

For the record Tier3 have also taken my downstream speed down to 12mb or so and tweaked my SNR. This has given me a totally stable line that is still giving me the 10mbps but without ANY dropouts. It's now a fab service and lightning fast. I've also taken off UPnP (or whatever it is) and connect at Auto 108. I'm using channel 6 wireless (because it's away from my neighbours services - I checked with MacStumbler). Best of luck to everyone else who is having problems and do persevere with tier3 support, it's well worth it.

[Saturday]

Trying to judge changes to MTU by eye sounds a little hit and miss!

MTU (maximum transmission unit) tells you the largest packet size that can be sent without fragmentation. Too big an MTU and packets have to be fragmented (bad), too small and you're not optimising your connection as you're having to send more packets (bad).

If you ping -f -l a site you'll come up with 1472 if you're on a SkyBB LLU product - or at least, that's what I get. Add 28 bytes for the IP/ICMP header and you get 1500 as the correct MTU figure to set.

So 1458 doesn't make sense. Now Connect is a different matter as 1458 is the recommended figure for the BT network.

[fredwestie]

its just the reduction on downstream speed to 12998 that's done it.
Either way, it's working like a dream so I'm loathe to fiddle while it's so good. I'll wait until it screws the pooch before tweaking any more.

[RichP]

If you ping -f -l a site you'll come up with 1472 if you're on a SkyBB LLU product - or at least, that's what I get. Add 28 bytes for the IP/ICMP header and you get 1500 as the correct MTU figure to set.

One word of caution - the ping command on linux, MacOS and I assume other UNIX-like systems works differently to the Windows one. The -f option doesn't mean "don't fragment", it means "flood" - send pings as fast as possible. The recipient site may not approve of this!