Re: [802.21] Comments on 21-06-0698-01-0000_IP_configuration_methods_IE.doc
Daniel,
On Mon, Aug 07, 2006 at 07:14:53PM +0900, Soohong Daniel Park wrote:
(snip)
> >>
> >> >
> >> >Second, if it is allowed to run DHCPv6 before running router
> >> >discovery, then it should be possible to run DHCPv6 and router
> >> >discovery in parallel regardless of the use of proposed IE or even
> >> >regardless of the use of 802.21.
> >>
> >> No, To run DHCPv6 on the host, it should get a related information
> >> from router (Router Advertisement [Managed flag] = set), then the
> >> mobile station can start sending DHCPv6 Solicit message. If no RA
> >> (host timeout), the mobile station can also start initiating DHCPv6
> >> operation. From the real experience, it spends at lease a couple of
> >> seconds or more. Yes, it is an existing limitation from the IETF
> >> perspective, but we can live with 802.21, and I don't see any trouble
> >> to make use of the facilities of 802.21 to resolve those limitations.
> >
> > If IETF does not allow parallel runs of DHCPv6 and router discovery
> > how can 802.21 resolve the limitations without violating IETF
> > protocols?
>
> Well, what I tried to explain above was for IPv6 address
> configuration procedure without 21 support. In that case,
> we can't run them in parallel. But, MIH Function can toss
> a relevant hint generated by lower layer to the upper layer.
> and DHCP works accordingly.
>
> There is no violation against IETF standard. If a link has
> no routers (RA support), host use the DHCPv6 to obtain
> addresses after having sent a small number of RS as
> described in RFC2461. IP_Configuration_Method IE aims to
> reduce the delay caused by *a small number of RA*.
Even if DHCPv6 can start before receiving RA, router discovery will
need to run for the mobile to know the router address. So it seems
that the execution order of DHCPv6 and router discovery is just
swapped, and the entire IP bootstrapping procedure does not appear to
be optimized.
Yoshihiro Ohba
>
> Does it makes sense ?
>
> Regards,
>
> Daniel
>