[LARTC] ADSL Calculator

[Andy Furniss]

Andy Furniss wrote:
> Tobias Diedrich wrote:
> 
>> Hi,
>>
>> I've written a small javascript ADSL throughput calculator:
>> http://nukunuku.yamamaya.is-a-geek.org/~ranma/adsl.html
>>
>> Feel free to submit alternative presets (I currently have presets
>> for three german telecom speed variants: T-DSL (1000|2000|3000),
>> derived from
>> http://www2.lancom.de/kb.nsf/5d445c701b3ff52dc1256e7700297e5c/27c6ee1c3e3f74b0c1256e94004a433e?OpenDocument). 
>>
>>
>> Comments, suggestions, spelling nitpicks?
>>
> 
> Looks good - one picky point - if your overhead means only 4 bytes 
> padding at default mtu are needed, then reducing mtu to be "optimal" for 
> IP and above levels may be less efficient from the point of view of the 
> tcp data because of the reduced payload vs fixed overheads.
> 
> I haven't done the maths on that :-)

Which I should have done first :-)

If timestamps are off it's still about 1 1/3 bytes per frame more 
efficient. If they are on (default on linux costing 12 bytes) the 
smaller mtu is about 1 byte per frame less efficient.

Andy.