> There is supposedly a magic feature by which one can attach two SLIP or
> PPP interfaces to a single remote host, i.e., have two serial (presumably
> modem) lines going from point A to point B, and get, in effect, a single
> double-width line.  A friend assures me Linux can do this; does anyone
> know if NetBSD can as well?  We have some interest in finding out, because
> I'm having some reliability problems with the Linux machine in question,
> and considering advocating a switch.

With PPP, anyway, there is a standard protocol for doing this,
Multilink Protocol (MP), RFC-somethingorother.  I don't know if Linux does
MP, or if it has some evil, skanky hack that works most of the time.