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[smoo]

Hello everybody, my first post.
Something weird happened today.   I was messing with the mtu setting, following the instructions on this site, using ping to find the maximum.  In the end I set the router and pc to 1500.  Ping checked ok with no df.  When I did a speed test it had jumped from my usual 2mb to 6mb.  My isp is aol, and so i had set the router to 1450 as recommended.  My contract is/was for 2mb, though this has finished.
So can changing the mtu make this big a change?

[jid]

Could you post your Router stats:-

http://www.kitz.co.uk/adsl/frogstats.php

It sounds like when you were applying settings on the router it may have resynced?

The stats with reveal all

[kitz]

Hi and welcome.

Well I have heard of the MTU making a big difference.. some people have reported a few Mb, but I dont think Ive seen one jump as much as yours, so in may in part have co-incided with something else going on?
In theory if the MTU is set too high then that's when packets get dropped and speeds can take a nose dive.
If the MTU is set too low then more packets than necessary are sent, which slows speeds down slightly by increasing the overheads.
That's why using the optimum MTU figure for your own line is recommended - although 1430/1458 works well for many.

Changing the RWIN can also make a help, and I've personally seen speed increases through that too..  thats were Ive  seen some big differences on my own personal line.

[smoo]

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 331384 582175 0 353 7401 27:14:12
LAN 10M/100M 25511479 22730423 0 440 356 2159:19:16
WLAN 11M/54M 6243537 3992333 0 1520 200 599:08:02
 

ADSL Link Downstream Upstream
Connection Speed 8128 kbps 448 kbps
Line Attenuation 22 db 5 db
Noise Margin 6 db 24 db

I'm sure the connection speed has been 8128kbps for some time, and I assumed aol did something to cap it at 2MB/s. 
Whatever I did its still working, still getting 6MB/s


 

[jid]

Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoA 331384 582175 0 353 7401 27:14:12
LAN 10M/100M 25511479 22730423 0 440 356 2159:19:16
WLAN 11M/54M 6243537 3992333 0 1520 200 599:08:02
 

ADSL Link Downstream Upstream
Connection Speed 8128 kbps 448 kbps
Line Attenuation 22 db 5 db
Noise Margin 6 db 24 db

I'm sure the connection speed has been 8128kbps for some time, and I assumed aol did something to cap it at 2MB/s. 
Whatever I did its still working, still getting 6MB/s

I am sure as Kitz would agree, those are great stats! You have quite a short line and must live close to your exchange.

It looks like AOL are capping you at 6meg as with a sync of that you should in reality get 7.1 ish.

[smoo]

This is what I am consistantly getting, I've been rounding down  8)

[jid]

This is what I am consistantly getting, I've been rounding down  8)

Actually thats around about right for the Sync speed you are getting!

As I said, those are excellent stats but it seems that if your Sync had always been that speed, the MTU tweak you did definitely did the trick! 

[kitz]

AOL use 512, 1Mb + 2Mb caps at their end.  There was mention at one point of a 4Mb capped product but I dont think it ever came to fruition.

Although I cant say for certain, that looks like an IPStream account. I believe TT now have control over AOL's central pipes and many users have maintained that their are more signs of congestion. 
Therefore it could now be contention that is limiting the max throughput to 6Mb..  you could always try a speedtest at around 6am or something to see if its any better then.

>> I'm sure the connection speed has been 8128kbps for some time

It probably was - about a year ago AOL "maxed" their IPStream lines, but capped them at their end which artificially limited the connection speeds to those mentioned above.

>> Whatever I did its still working, still getting 6MB/s

Thats excellent news - in fact 6Mb could also be contention at the local exchange.  It wasnt unusual for me to see figures around that region if my exchange was busy, and I was only getting those speeds (or less) during peak times.. not down to the ISP, but the exchange.

oooh.. WAIT!.... Something else has just this min occurred to me right now whilst typing.. 
I have actually seen first hand speeds limited to around 2Mb during peak times.. that was purely down to an incorrect MTU setting, that only kicked in when contention was also occurring.

I'd forgotten all about this... but you say you set it in the router too?  Because the time that I saw this happen.. tweaking on the PC didnt make any difference - and it wasnt until the settings in the router was changed that the problem vanished.

I wonder ??

[kitz]

This is what I am consistantly getting, I've been rounding down  8)

That wasnt there when I started the reply above.   Youre speeds are more or less spot on 

[smoo]

The exchange I'm connected to is ipstream only, something I found out on this excellent website   I've already recommended it to a friend.
I was thinking of changing isps, but now I've somehow got 6.9MB/s I might not.
Still getting 6.9 even now, assuming these are peak times, contention does not appear to be a problem.

[kitz]

Indeed theres certainly no sign of contention, and thats a damn good speed for this time of day

Whatever happened - it works 

[smoo]

Spoke too soon, back to 2MB/s now
Time to change isp I think

[kitz]