capping internet usage in holdiay let

Hi
My sister lives in rural spain and lets out a cave for which she supplies wifi internet access.
Because of where she lives she has a relatively expensive data plan with a monthly cap.
The wifi access she provides is really just to allow the guest to check email and check flights and things, however some guests abuse this and she suddenly finds her monthly allowance has vanished.
Is there any way she can limit the guests usage so that this doesn't happen.
thanks
Steve

Yes but it would have to be done at the router level.

With a properly setup decent quality router this configuration is possible. You probably cannot do it with the routers you get free from ISPs - would need a Draytek or similar.

Also is it that simple - with a monthly usage cap how would you share it between weekly (or shorter) lets? The first let of the month could use all the allowed usage.

Could charge separately for internet access to cover the cost?

Depending on router, perhaps set wireless b rather than g, disable all protocols other than mail and http.

Get a fon spot, make them pay to use it and limit the speed to 512k if it's only for web/emails.

Hi,
could you point me to a specific router model that will let you do this.
the monthly usage cap also covers her internet usage as well, so really she only want to allow the guests a smallish amount enough to cover a bit browsing and email.
thanks
Steve

thanks that looks interesting, I hadn't heard of fon before, I'll pass it onto my sister.
thanks
Steve

Your sister may also limit the time[s] that the wireless is enabled in the cave. The 'guests' are seeing it more as a wee extra to abuse since they're there.

They have absolutely no knowledge of any limits really, and no sense of respect.