Not sure on this one terminate cause:

Jaye Mathisen (mrcpu@cdsnet.net)
Tue, 31 Dec 1996 15:56:14 -0800 (PST)

S2: Session Terminated - User Error - PPP NCP Active to Request
S2: Session Terminated - Lost Carrier

First, it lists 2 reasons, which seems problematic, and User Error is
documented on the Livingston home page, but not the "PPP NCP Active to
Request" part.

This from the console.

Also, I got a Session termination from PPP Maximum Retransmissions, but
not sure if this is a tweakable parameter, or indicative of something
else.