On Mon, 18 May 2015, Jonathan Morton wrote:

> I've gone for the technical labels for three reasons. First, it reflects
> what's actually happening, which generally reduces confusion in the long
> run. Second, you might underestimate the number of ADSL ISPs worldwide, as
> well as the difficulty of keeping such a database up to date. Third, every
> DSL modem and ISP I know of has made it reasonably easy to discover at
> least the base encapsulations - autodetection of vcmux vs llc isn't
> absolutely reliable, for example. They might be less forthcoming about vlan
> and FCS, but one can make intelligent guesses here, based on whether it's a
> converged services ISP.

offer both the official labels and some easy-to-understand boxes to use

for example

underlying packet size (ATM = 48, Ethernet = 1500)

protocol overhead (various examples)

David Lang

> Ideally, we could do with a tool (at dslreports?) which makes detecting the
> actual overhead easier. This would be doable using small packets to magnify
> the differences.
>
> And if the user really can't work it out, they can always throw up their
> hands and specify "conservative".
>
> - Jonathan Morton
>