The later changes were only cosmetic, cause problems in IPv6-only-
connections (reported by Wolfgang Solfrank in private mail), as well
as reintroducing the original bug again.
As long as we receive data from the peer, don't worry. When we have not
received anything within the "max_noreceive" period, we start sending LCP
echo requests and count them, until we receive an answer (or some data)
or the "maxalive" count of not answered echo requests is reached.
All this is checked at a global 10 seconds interval for all interfaces.
The "max_noreceive" period and the "maxalive" count are configurable per
interface.
Hopefully this will fix ALTQ for ISDN and PPPoE interfaces.
While there remove an unsued function which contained dubious code
(accessing interface queue internals w/o the proper macros).
a configurable maximum (default: 5).
Some ISPs shut down accounts (at least temporarily) after to many bad
retries. This hit me recently due to a stupid pilot error and the fast
retry rate.
