RE: Call for v6ops agenda items

[<teemu.savolainen@nokia.com>]

>-----Original Message-----
>From: ext Cameron Byrne [mailto:cb.list6@gmail.com]
>Sent: 16 February, 2010 15:55
>To: Mikael Abrahamsson
>Cc: Savolainen Teemu (Nokia-D/Tampere); joelja@bogus.com;
>v6ops@ops.ietf.org; fred@cisco.com; 3gv6@ietf.org
>Subject: Re: Call for v6ops agenda items
>
>Instead of answering these questions, tell me what is so wrong with
>giving a mobile user (cell phone! security camera, electricity meter
>...) a /112 or something similar?  Why is it so important that the
>3GPP specs REQUIRE a /64, and consequently the vendors don't support
>anything else?  Really, GGSN vendors only support /64 ....

Well, timing at least. We should now deploy v6, not discuss on link models. Remember RFC4682 SLAAC that says:
--
5.5.3.  Router Advertisement Processing

   For each Prefix-Information option in the Router Advertisement:

....

      If the sum of the prefix length and interface identifier length
      does not equal 128 bits, the Prefix Information option MUST be
      ignored.  An implementation MAY wish to log a system management
      error in this case.  The length of the interface identifier is
      defined in a separate link-type specific document, which should
      also be consistent with the address architecture [RFC4291] (see
      Section 2).
--

So in addition to dynamic prefix length, you'd need to have some sort of dynamic interface identifier length? More specification work...

One additional reason is unification with Ethernet and other link types. You can have simple IPv6 stack implementation that assumes 64 bit IID and /64 prefix, and therefore can work easily with different kinds of links. I.e. you can separate modem and IP stack implementations more easily.

With /64 prefix you can bridge (or rather ND Proxy) the cellular interface to (W)LAN. If you'd have /112, how to bridge/proxy? 

Best regards,

Teemu