When you look at the actual timings, those which are "user request" have about a 1.min interval between the end of the previous session and the start of the next. This suggests a reboot/resync of the modem/router. Whether the log is able to distinguish between a drop in sync and a user forced reboot, I don't know as I've not seen logs where these different events have occurred.
The one that is "administrative reset" has no time gap between end of session and start of next, but there was a change of IP address. This suggests that the ppp session (not sync) was terminated, somewhere between the exchange and PN, either down to BT, or perhaps PN or the user forcing a Gateway change (the latter by using the disconnect button on the modem/router interface).
Now if I've understood this right, those logs (RADIUS or not) do not definitively show drops in sync, only a drop of session. I've seen other logs where PN have said loss of sync and compared to user logs where there is no change in sync speed etc. or loss of sync, it can only be ppp session dropped.
James, I know you have an extremely good knowledge of most things, but you ought to be able to confirm this by speaking to one of your knowledgeable experts.
With regard to Dan's last comment, his line's been repaired, he seems to be simply requesting that his Target SNRM is reset.
