Re: Start/Stop packets / real-time user accounting not possible

William Bulley (web@merit.edu)
Wed, 14 Aug 1996 11:09:23 -0400 (EDT)

According to Steve Hsieh:
>
> I have 'no hangup' on so that when someone connects via a dumb terminal
> session, they can log into one host, log out, and log into a different
> host without having to log off. I don't see why this meant for abnormal
> operation. Since we are not really an ISP, but rather
> provide connectivity for our (university) departmental users who have
> accounts on numerous machines, this seemed to make sense.
>
> Are you saying that to connect to two different hosts, it is common
> practice to force the user to hang up and dial back? Also, having no
> hangup set also allows one to do things like display a message of the day,
> view who's currently logged in (through a telnet session to pmwho), etc.
> Merit sets 'no hangup' as well, and they take full advantage of it,
> offering help screens through gopher and the like. Ctrl-D still serves
> the purpose of dropping DTR and hanging up. [I wonder how they figure out
> the difference between a STOP and an MODEM_STOP, both of which are defined
> in their Merit radius LAS code)]

Yep, it is so "abnormal" that people may have forgotten why we asked for
this feature when RADIUS was first being designed (before my time BTW!)
by the folks at Livingston...

Steve has described this feature's usefulness to him and his department
and, by induction, to hundreds of thousands of users throughout MichNet.

It is true that this feature makes RADIUS accounting a challenge (which
is why we added the Modem-Stop value to the Acct-Status-Type attribute.
We (Merit) have a concept of a "modem" session which is distinct from
the Livingston concept of a "telnet" session. By (our) definition one
"modem" session may be comprised of zero or more "telnet" sessions. All
this discussion is WRT to dumb terminal connections BTW. The Framed
stuff (PPP and SLIP) works just fine. By definition, one "modem" session
ties up one async line for the duration of the connection/call.

I'm still searching for better terms for "modem" session and for "telnet"
session BTW. :-)

Regards,

web...

-- 
William Bulley, N8NXN              Senior Systems Research Programmer
Merit Network Inc.                 Domain: web@merit.edu
4251 Plymouth Road                 MaBell: (313) 764-9993
Ann Arbor, Michigan  48105-2785    Fax:    (313) 747-3185