Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!aero!aerospace.aero.org!obrien
From: obrien@aeroaero.org (Michael O'Brien)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Mobile TCP/IP (was Re: Can subnets be separated by another net?)
Message-ID: <78479@aerospace.AERO.ORG>
Date: 17 Jul 90 16:22:37 GMT
References: <9007121332.AA02890@chiya.bellcore.com> <9007121800.AA01850@xap> <153@tots.UUCP> <269E07C3.604D@intercon.com> <64290@sgi.sgi.com> <139016@sun.Eng.Sun.COM>
Sender: news@aerospace.aero.org
Reply-To: obrien@aeroaero.org (Michael O'Brien)
Organization: The Aerospace Corporation
Lines: 36


In article <139016@sun.Eng.Sun.COM>, grw@cabernet.Eng.Sun.COM (Gregory
Whitehead) writes:
|> In article <64290@sgi.sgi.com> rpw3@sgi.com (Rob Warnock) writes:
|> >In article <269E07C3.604D@intercon.com> amanda@mermaid.intercon.com
|> >(Amanda Walker) writes:
|> >+---------------
|> >| In article <153@tots.UUCP>, tep@tots.UUCP (Tom Perrine) writes:
|> >| > I hate to admit it, but the cell-phone (phone system) model of
|> >| > addressing does have many advantages for the *user*. No matter where
|> >| > you go, your logical address (phone number) follows you.
|> >Automatic for the roamer dialing out; that's half. But now many (most?)
|> >cellular companies offer a hack such that if you dial a person's cellular
|> >number in their home area *and* they're currently known to be roaming
|> >somewhere (they've placed a roming call within the last 24 hours), the
|> >home area system will give you an intercept recording which tells you
|> >they're out of area... *and* gives you the roamer access number where
|> >they are. Sort of an ICMP Redirect...   ;-}    ;-}
|> 
|> Actually, GTE offers "Follow Me" Roaming in many foreign areas now.
|> The roamer simply registers in the foreign area (by dialing *18) and
|> all calls are forwarded automagically.

The non-wireline services in California have recently banded together to
permit this in an even easier fashion, as I recall.  As best I can figure
out, they must all send any roamers who've acquired the system in to a
central clearinghouse all the time; anyone who calls your number back
in your home area gets forwarded to you ALL THE TIME, unless you
SPECFICALLY send a code that turns the service OFF.  The manual warns
that you'd better cancel this (or it self-cancels at midnight) when you
return home or you won't get any calls THERE, either.

Now THAT'S an ICMP redirect.
--
Mike O'Brien
obrien@aerospace.aero.org