Re: ITU-T Dubai Meeting and IPv15
One problem with excessively large fields, including variable length addresses with a high maximum length, is that the next time someone wants to encode some additional information, they just tuck it inside that field in some quasi-proprietary way, instead of going to the trouble of actually adding a field. Witness X.509 Certificate serial numbers, which are arbitrary precision integers, but which frequently are used for a variety of information, all BER encoded... Thanks, Donald = Donald E. Eastlake 3rd +1-508-333-2270 (cell) 155 Beaver Street, Milford, MA 01757 USA d3e...@gmail.com On Fri, Aug 10, 2012 at 1:35 PM, David Conrad d...@virtualized.org wrote: On Aug 10, 2012, at 10:22 AM, Andrew G. Malis agma...@gmail.com wrote: Another alternative is self-describing variable-length addresses, again do it once and we'll never have to worry about it again. Heretic! That's OSI speak! Why do you hate the Internet you ISO/ITU lackey?!? /flashback Yeah, variable-length addresses would have been nice. There was even working code. Maybe next IPng. Regards, -drc
Re: ITU-T Dubai Meeting and IPv15
On 8/11/12 10:13 AM, Donald Eastlake wrote: One problem with excessively large fields, including variable length addresses with a high maximum length, is that the next time someone wants to encode some additional information, they just tuck it inside that field in some quasi-proprietary way, instead of going to the trouble of actually adding a field. Witness X.509 Certificate serial numbers, which are arbitrary precision integers, but which frequently are used for a variety of information, all BER encoded... given various semantic uses of bits within ipv6 addresses that have been proposed or which are used informally even with only 128 bits it's important to make this distinction. a freely extensible bit field will end up with all sorts of garbage in it, that at best is only signficant in one context, and at worse is significant in different fashions in different contexts. instead of having an locator-id you have a locator-qos-mpls-subscriberid-streetaddress-latlong-id Thanks, Donald = Donald E. Eastlake 3rd +1-508-333-2270 (cell) 155 Beaver Street, Milford, MA 01757 USA d3e...@gmail.com On Fri, Aug 10, 2012 at 1:35 PM, David Conrad d...@virtualized.org wrote: On Aug 10, 2012, at 10:22 AM, Andrew G. Malis agma...@gmail.com wrote: Another alternative is self-describing variable-length addresses, again do it once and we'll never have to worry about it again. Heretic! That's OSI speak! Why do you hate the Internet you ISO/ITU lackey?!? /flashback Yeah, variable-length addresses would have been nice. There was even working code. Maybe next IPng. Regards, -drc
Re: ITU-T Dubai Meeting and IPv15
A 260-bit address should be sufficient to address every atom in the universe, according to current estimates (10^78 atoms). We go there next (plus some extra to add hierarchy), and we'll never have to worry about addressing again. Another alternative is self-describing variable-length addresses, again do it once and we'll never have to worry about it again. Cheers, Andy On Thu, Aug 9, 2012 at 12:45 PM, Worley, Dale R (Dale) dwor...@avaya.com wrote: From: Phillip Hallam-Baker [hal...@gmail.com] As Tom Knight pointed out when the IPv4 address size was chosen, there aren't enough for one for each person living on the planet. Remember that we are trying to build a network that is going to last for hundreds if not thousands of years. Technology changes over time, and so the optimal design tradeoffs change over time. When IPv4 was designed, memory, processing power, and transmission capacity were far more expensive than now. Moore's Law suggests a factor of 2^15 between 1982 and 2012. Before that was the ARPAnet, with 8 bit addresses, which lasted for around 15 years. Presumably IPv6 will suffice for at least another 30 years. The real issue regarding longevity is that total network overhauls should be infrequent enough that their amortized costs are well less than ongoing operational costs. Once that has been achieved, the cost savings of designing a protocol with a longer usable lifetime is probably not worth the effort of trying to predict the future well enough to achieve longer lifetime. Extrapolating a 30-year lifetime for each IP version suggests that in 300 years we will reach the end of the usable life of IPv15 and will have to allocate more bits to the version field at the beginning of packets. That'll be a mess... Dale
Re: ITU-T Dubai Meeting and IPv15
From: Andrew G. Malis agma...@gmail.com 260-bit address should be sufficient to [s]address[/s] _name_ every atom in the universe YPIF. Noel h
Re: ITU-T Dubai Meeting and IPv15
On Aug 10, 2012, at 10:22 AM, Andrew G. Malis agma...@gmail.com wrote: Another alternative is self-describing variable-length addresses, again do it once and we'll never have to worry about it again. Heretic! That's OSI speak! Why do you hate the Internet you ISO/ITU lackey?!? /flashback Yeah, variable-length addresses would have been nice. There was even working code. Maybe next IPng. Regards, -drc
RE: ITU-T Dubai Meeting and IPv15
From: Phillip Hallam-Baker [hal...@gmail.com] As Tom Knight pointed out when the IPv4 address size was chosen, there aren't enough for one for each person living on the planet. Remember that we are trying to build a network that is going to last for hundreds if not thousands of years. Technology changes over time, and so the optimal design tradeoffs change over time. When IPv4 was designed, memory, processing power, and transmission capacity were far more expensive than now. Moore's Law suggests a factor of 2^15 between 1982 and 2012. Before that was the ARPAnet, with 8 bit addresses, which lasted for around 15 years. Presumably IPv6 will suffice for at least another 30 years. The real issue regarding longevity is that total network overhauls should be infrequent enough that their amortized costs are well less than ongoing operational costs. Once that has been achieved, the cost savings of designing a protocol with a longer usable lifetime is probably not worth the effort of trying to predict the future well enough to achieve longer lifetime. Extrapolating a 30-year lifetime for each IP version suggests that in 300 years we will reach the end of the usable life of IPv15 and will have to allocate more bits to the version field at the beginning of packets. That'll be a mess... Dale
