Brett,
OK, thanx that wasn't clear to me. I agree that the number of links will
increase. Route optimization certainly will help, and I am not disputing
that.
jak
----- Original Message -----
From: "Brett Pentland" <[EMAIL PROTECTED]>
To: "James Kempf" <[EMAIL PROTECTED]>
Cc: "Charles E. Perkins" <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Wednesday, May 29, 2002 9:43 PM
Subject: Re: Mandating Route Optimization
> Hi,
>
> Sorry if I'm butting in or completely off the mark but I got the
> impression from Charles' email that when talking about a capactity
> multiplier, he was referring to the number of links that packets have
to
> traverse to get to their destination, rather than the overhead imposed
> by tunnelling headers. For example, a route optimised VoIP stream
might
> use up 30 kb/s on, say, two links rather than on twenty.
>
> Cheers,
> Brett.
>
> James Kempf wrote:
> <snip>
> > > > But, for now, it is very easy to see the extra amount of work
> > route
> > > > optimization would add to implementing an IPv6 stack, but very
hard
> > to
> > > > see what effect lack of route optimization would have on traffic
> > flow in
> > > > the Internet when mobile nodes are widespread
> > >
> > > Here are some facts:
> > >
> > > A. A mobile device transmitting data to a correspondent node will
> > > require forward and reverse tunneling through the home network
> > > unless it can establish a binding cache entry at the
correspondent
> > > node.
> > >
> > > B. This can increase the total capacity requirement for the
> > > communications by an arbitrary amount, depending on the
> > > layout with respect to the home network. That could easily
> > > mean a factor of "thousands".
> > >
> > > Opinion:
> > >
> > > A typical multiplier for (B) will be about 2. The actual
> > > number depends on the relative placement of the nodes, and
> > > the multiplier will be higher whenever a mobile device needs to
> > > communicate with a local correspondent.
> > >
> >
> > We are talking about adding the tunnel header, right?
> > If so and if you mean the relative volume of the data traffic
> > will be increased by a factor of 2, that, of course, depends on the
> > packet size. If the packet is a 40 byte VoIP packet, then I agree
> > with you. If it is a 1500 byte HTTP packet (most common size
> > on the Internet today, I'm told) then the relative increase won't be
> > nearly as large. People are more likely to look at the latter than
the
> > former when they consider route optimization because most of the
traffic
> > now is of that nature. This may be shortsighted, but it is
> > how practical-minded people (which means most engineers)
> > tend to think
> >
> <snip>
>
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Brett Pentland [EMAIL PROTECTED]
> CTIE - Centre for Telecommunications and Information Engineering
> Department of Electrical and Computer Systems Engineering
> PO Box 35, Monash University, VIC, 3800, Australia
> Phone : +61 3 9905-5245 Fax : +61 3 9905-5358
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
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