MTU Set to 1500... tests showing 1480?

[Damolee]

Hi there folks, got a problem which is seriously starting to bother me.

I am using a PPPoA ADSL Router, in the settings I have set the MTU values to 1500, aswell as in Windows using TCP Optimiser.

But when I am running all online based tests, it is showing the value as 1480 which is incorrect, tried various sites and getting the same results.

I have updated the firmware on my Router, and now at a complete loss as what to do.... is this normal whilst using a router? They are a new concept to me, its a Dynamode R-ADSL C4S ....

Does anyone have any ideas? ....as I know this will throttle what was before hand a good connection with my standalone internal ADSL modem.

Much appreciated,

- D -

 

[Grayfox]

Adsl can't do more then 1450mtu or it won't be able to sync to the isp.(Most optimal on my line is 1430)

 

[Damolee]

Sorry to say but that isn't true.

Previously my MTU was set to 1500 and it ran speedy without any problems, that was using a standalone ADSL Internal modem.

The router can be set above 1500 MTU, the modem built in cant and there is no support or better firmware, bloody thing.

 

[nuke]

what is MTU guys?

 

[fitzjj]

MTU = maximum transmission unit.

Damolee, it is true PPPoA packets are smaller than PPPoE, hence the incompatibility between PPPoA and PPPoE.