Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!sdd.hp.com!ucsd!ames!sgi!rpw3@rigden.wpd.sgi.com
From: rpw3@rigden.wpd.sgi.com (Rob Warnock)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Mobile TCP/IP (was Re: Can subnets be separated by another net?)
Message-ID: <64290@sgi.sgi.com>
Date: 17 Jul 90 03:22:48 GMT
References: <9007121332.AA02890@chiya.bellcore.com> <9007121800.AA01850@xap> <153@tots.UUCP> <269E07C3.604D@intercon.com>
Sender: rpw3@rigden.wpd.sgi.com
Reply-To: rpw3@sgi.com (Rob Warnock)
Organization: Silicon Graphics, Inc., Mountain View, CA
Lines: 32

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.
| 
| In all of the cellular systems I've used so far, roaming is only half
| automatic.  In particular, to place a call to a roamer, you have to dial
| the roamer access number for the area where they are, and then dial their
| phone number.  This amounts to source routing, which is even more of a
| pain for mobile destinations than it is for "static" ones.  Bleah.
+---------------

In fact, most of the current cellular romaing systems are 3/4-automatic... ;-}
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...   ;-}    ;-}


-Rob

-----
Rob Warnock, MS-9U/510		rpw3@sgi.com		rpw3@pei.com
Silicon Graphics, Inc.		(415)335-1673		Protocol Engines, Inc.
2011 N. Shoreline Blvd.
Mountain View, CA  94039-7311