Can someone from PN please try to sort this PPP dropping malarky!

[#1]

Quote from: darkskye

@Mand It is possible for a line to drop its sync and not drop the ppp session, if sync returns quickly enough. (I think this has happened to me recently, is the ppp up longer than the line up in the sig image? ---\/)

Not wishing to muscle in (Mand will have more first-hand knowledge than me no doubt!), but you might find this interesting. .  http://en.wikipedia.org/wiki/Point-to-Point_Protocol. Look at "PPP line activation and phases" about two thirds of the way down.
The router checks at regular intervals in conjunction with the PPP layer. I guess if the DSL disappears sufficiently quickly as to be logged but between handshake checks then the answer might be "yes" to your question. Interesting one this one...  anyone any more ideas?

[#2]

nozzer, I think the key factoid I omitted is that my hardware which maintains my sync (netgear DM111) is not the same as my hardware that provides my PPP session (home built FreeBSD machine using pppoe and FreeBSD's firewall and nat services), so when my line drops there is no "Line down, bring my ppp session down and wait for the line to return and restart ppp" which is what most routers appear to do.

[#3]

Yes, but, to quote the bard..

Link Termination Phase.This phase closes down this connection. This can happen if there is an authentication failure, if there are so many checksum errors that the two parties to the link decide to tear down the link automatically, if the link suddenly fails, or if the user decides to hang up his connection. This phase tries to close everything down as gracefully as possible depending on the circumstances.
Even though your kit has separate physical elements the PPP should still use the DSL part as a passthrough to you, so if the essential bit a your end disappears (maybe because of a DSL drop) it should still try to drop/re-establish the PPP session, unless the DSL drop is so short as to be completely missed. Flying blind a little here with your setup.

[#4]

Just to translate

Quote from: darkskye

netgear DM111

is a broadband modem

Quote from: darkskye

FreeBSD

is a Unix-based operating system.

[#5]

But the system overall must still use PPP to authenticate surely? If the DSL fails via the DM111 the PPP should close the connection on the backhaul. The only thing I can think of is that the DSL is lost so briefly that it logs on the DM111 but between authentication checks, so no PPP drop. Or not, as the case may be! 
dick:quote