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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
