Well, if you're offering service using this, you need to look at this from a
support perspective too.  If we give everyone a private address behind a NAT
device, we're going to have all sorts of people calling because they can't
play Warcraft III, or whatever the game of the day is.  It does offer the
benefit of a bit more security for people on the network, but in all
reality, 90% of users don't care about security and they just want their
online games to work.  Many people who get broadband get it specifically to
play games on.  There is some firewall trickery that we could probably use
to get most protocols to work, but there are still going to be things that

As far as roaming goes, using public IP's isn't going to change the
functionality of that at all.  Your border router routes for your public
address range, and your routers on the inside handle the individual routes
for each ip and tell the border router(s) how to get there.  This can get
messy though depending on how many subscribers you have and what routing
protocol you use.  You don't want to be flooding LSA's all over the network
everytime someone connects, disconnects, or switches to a new access point.
I think Richochet handled this by making all of their access points connect
to a central bridge so it was all one big broadcast domain.  That way, they
didn't have to handle route propagation everytime someone switched to a
different AP.  

Plus, how viable is roaming with 802.11 or Canopy?  GSM 1800/1900 has
special provisions for handling frequency shifts due to the doppler effect,
since many people talk on their phones while driving.  Has the 802.11 spec
or Canopy been developed with mobile (as in driving) users in consideration?
While GSM has standard provisions for this, you will lose your signal when
the distance between you and a repeater is changing faster than 280km/hr.
While no one normally drives that fast, if wireless data protocols were not
designed with this in mind the speed at which you will lose your signal may
be considerably less.  Roaming is a nice to have, but for the most part it's
probably not going to be a reality because you would literally have to
blanket the city with access points, the cost would be astronomical.  Just
look at Ricochet, they did it, but then went bankrupt in the process.  A lot
of that was their marketing department's fault, but their mistakes make a
nice lesson for others.


> -----Original Message-----
> From: Carl Wilhelm Soderstrom [mailto:chrome at real-time.com]
> Sent: Monday, July 22, 2002 6:16 PM
> To: tcwug-list at tcwug.org
> Subject: Re: [TCWUG] Richochet boxes?
> > If it comes to the point where we'd start selling access 
> and charging
> > people, we'd have to get some other form of connectivity, 
> and we're also
> > going to need, at minimum, a couple of /24's.  
> not necessarily. depends what kind of service we're offering. 
> I don't think
> it's entirely unreasonable to just use a 10-net for our 
> city-wide wireless
> network. we'd be able to run servers or whatever for our own 
> benefit; and if
> you *really* wanted to make them visible to the outside world 
> (and couldn't
> get a wired connection for some reason), what about begging 
> or borrowing
> some loose IP addresses from someone with a gateway willing 
> to forward them
> on to your internal address?
> help me understand what you're saying: what did you have in 
> mind, that we
> need public IP addresses for? certainly there are plenty of 
> uses for them;
> but we may be in something of a bandwidth-constrained situation fairly
> quickly, and so servers/IP phones may have their 
> functionality curtailed
> severely if they're depending on wireless and don't have a landline to
> provide (sort-of-guaranteed) bandwidth.
> I've also heard this sort of scheme discussed as a way to do roaming
> wireless... you have a static IP address on your device, and 
> whenever you get
> handed off to a new access point, that AP just routes the traffic back
> across the network (using BGP or whatever to find the route) 
> to whatever the
> former gateway was.
> Was it Spencer who brought that idea up?
> Carl Soderstrom.
> -- 
> Network Engineer
> Real-Time Enterprises
> www.real-time.com
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