Just to complement Stuart's position

-----Original Message----- From: stuart.prevost@bt.com [SMTP:stuart.prevost@bt.com] Sent: Thursday, July 13, 2000 3:48 PM To: ngtrans@sunroof.eng.sun.com; ipv6-wg@ripe.net; mir@ripe.net; ipng@sunroof.eng.sun.com; sig-ipv6@apnic.net; richardj@arin.net; Daniel.Karrenberg@ripe.net; joao@ripe.net Subject: (ngtrans) IPv6 Policy Document Revision suggestion

From reading all the emails it seems that the /48 approach as the *minimum* allocation is the way the IETF would like IPv6 deployment to proceed. However, as it has been demonstrated, the /35 allocations today would only allow for 8,192 /48 per subTLA, and this is assuming that the subTLA holder hasn't split up the NLA block so they can allocate to other providers, in which case this figure could be as small as 256 or lower!!!!

I see this as the reason why ISPs consider /48 for a home customer as too large, and hence the sliding-window & /56 discussion at the last RIPE meeting.

Note that we recognise the benefits of /48 for multihoming/rehomeing and maybe more importantly to make sure that IPv6 NAT will *never* become a reality! Thus, as an ISP, we support /48 allocations if can be confident that we can get enough of them; i.e.: we get /29s instead of /35s.

Now, if the /48 allocation is the way to proceed, I feel that all initial /35 allocations should be initially changed to /29 as the first step. This can be done easily as all allocations have the /29 reserved to ensure a contiguous block. However a /29 allows for 524,288 /48, again if the whole subTLA is used. So at the same time the 80% utilisation section of the document needs to be worded correctly to allow ISPs to apply for subsequent subTLA's.

That is: the 80% (or whatever utilisation) to refer to the number of /48s in a subTLA since ISPs will have no control over how and when our customers, home users, SOHOs, mobile users are going to utilise their /48 prefix! Regards George