User PPP was introduced to FreeBSD in release 2.0.5 as an addition to the existing kernel implementation of PPP. So, what is different about this new PPP that warrants its addition? To quote from the manual page:
This is a user process PPP software package. Normally, PPP is implemented as a part of the kernel (e.g. as managed by pppd) and it is thus somewhat hard to debug and/or modify its behavior. However, in this implementation PPP is done as a user process with the help of the tunnel device driver (tun).
In essence, this means that rather than running a PPP daemon, the ppp program can be run as and when desired. No PPP interface needs to be compiled into the kernel, as the program can use the generic tunnel device to get data into and out of the kernel.
From here on out, user ppp will be referred to simply as ppp unless a distinction needs to be made between it and any other PPP client/server software such as pppd. Unless otherwise stated, all commands in this section should be executed as root.
There are a large number of enhancements in version 2 of ppp. You can
discover what version you have by running ppp with no arguments and
typing show version at the prompt. It is a simple matter
to upgrade to the latest version of ppp (under any version of FreeBSD)
by downloading the latest archive via
www.Awfulhak.org.