Subject: RE: [mobile-ip] Thoughts on using handover capability extensio

From: [email-masked]
Date: Thu, 14 Nov 2002 16:41:03 -0600

> > - it seems to me that folks prefer moving the PrRtSol
> >    and PrRtAdv messages to an earlier time. Perhaps
> >    we should recommend that the MN should send
> >    PrRtSol after router discovery (RS/RA) or during router
> >    discovery (see the next issue) ? In this message,
> >    the MN sends a wildcard for target APs.
> 
> The MN should also send some indication of the link 
> technology, for intertech handover, in addition.
> 

Why? I am not sure if link technology knowledge is 
required for network layer HOs. Is this required in
the PrRtAdv to awaken some idle interface at the MN?
This would imply that the pAR knows what types of link
technologies the MN can move to. Not feasible.

-Basavaraj

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From: "James Kempf" <[email-masked]>
Date: Fri, 15 Nov 2002 03:04:34 -0800

> the PrRtAdv to awaken some idle interface at the MN?

One of the original goals of the Seamoby work was to support intertechnology
handover. As described in the problem statement
(draft-ietf-seamoby-cardiscovery-issues-03.txt), the CARD work was supposed to
make this possible by allowing the MN to find out what link technology options
were available. As you say, this would allow a MN to obtain information on
inactive interfaces over an active interface, and thus save power. For some
cases, such as a cdma2K interface providing informatoin on WLAN, this is a bit
problemantic, because the average cell size for cdma2k is so much larger than
for WLAN that a hotspot 1 km away might be advertised even though it was not
physically reachable. But for technologies where the cell sizes are closer, like
Bluetooth and WLAN in an airport, this could be more feasible.

> technologies the MN can move to. Not feasible.

Why is this any different in principle than the pAR knowing what access points
belong to a router in another subnet, which is what the quasi-reverse address
translation function is trying to achieve?

The routers are going to have to exchange information this, presumably using the
PrRtAdv, anyway.

            jak