[nsp] Rate - limiting

[sthaug at nethelp.no]

> Also isl adds a 40 byte header and dot1q adds only 8 bytes (or some
> numbers similar). I know its a small amount but every bit (or byte) helps
> :)

The actual numbers are important here: ISL adds 30 bytes, 802.1q adds 4.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no