PPPoE/PPPoA and MTU Settings!

Could any kind people enlighten me more on the optimum PPPoE/PPPoA and MTU settings should be for Zen ADSL? My business service connects with PPPoE, encapsulation type LLC/SNAP and 1500 MTU; however my residential service uses PPPoA, encapsulation type VC MUX and an MTU of 1498. In their setup guides, Zen mention that either PPPoE or PPPoA can be used but not which is preferential (I understand PPPoA has slightly less overheads compared to PPPoA). However, they don't mention anything about MTU. On this business connection this is set at 1500. The max that my residential connection will go to is 1498, which is odd since I thought that due to overheads on PPPoE (which my business connection is on), a PPPoA of higher than 1498 is not possible?

I have actually changed my residential MTU down to 1486, as this seem to provide slightly lower latency and packet loss. Whether this is just coincidence I'm not sure?

Thanks,

Dan

Anyone able to help?

MTU is a tuning issue, i.e. no single value works best for everyone, so you need to find out what works for you i.e. speeds and does not break SSL sites.

As for PPPoE or PPPoA (assuming its an ADSL modem with router built in) should not matter either way on either business or residential. If business line is direct to a Zen DSLAM then it might be different but thats a question only Zen can answer.