RE: [Seamoby] Minutes for Meeting at IETF 53

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Hi Karim,

-----Original Message-----
From: ext Karim El-Malki (ERA) [mailto:[e-mail]]
Sent: Wednesday, April 17, 2002 6:14 AM
To: 'Hemant Chaskar'; [e-mail]; [e-mail]
Subject: RE: [Seamoby] Minutes for Meeting at IETF 53


 > >  > In a single interface handoff situation, Layer 2 typically
 > >  > delivers the
 > >  > AP or AR L2 identifier to which the MN will be handed over. This
 > >  > information is required (by the MIP fast handover 
 > algorithms) at the
 > >  > MN's AR. So the issue is fairly simple: the AR must be 
 > able to do
 > >  > reverse address translation in order that it can contact the
 > >  > other AR.
 > >
 > >This is not really applicable to Mobile-Initiated MIP Fast Handoff.
 > >In Mobile-initiated we consider the useful case where the 
 > MN can recover
 > >the CAR IP address/es from the L2 trigger. The MN then sends a Proxy
 > >Router Solicitation (RtSolPr) to its curent AR containing 
 > one or more CAR
 > >IP addresses. This means that the source AR already gets 
 > the CAR addresses.
 > >So we can do without the AR doing translation or 
 > discovering geographical
 > >adjacency. The MN can pass these CAR address/es to the 
 > source AR for both
 > >single and multiple-interface MNs. So I think that the 
 > conclusion from the
 > >meeting is compatible with MIP Fast Handoffs.
 > >
 > >/Karim
 > 
 > [HC] I am wondering, if this useful case is genral enough. 
 > In other words, 
 > can MN always get IP addresses from AP beacons (or L2 
 > triggers) without 
 > having to acquire connectivity with AP. More so, in single NIC case.

[KEM] If you get a trigger at the MN you are somehow told
that you have to move and this could contain the network's desired
place where you should move (if it's multi-technology then one network
may not know all that is possible). Here it is assumed that these are
IP addresses or that the IP addresses can be easily recovered. The MN
collects the full list of CAR addresses and decides. At least that's
what I understood people wanted at the last meeting. Do you think it
is not generic enough since it relies on IP addresses recovered from
triggers?

[DOT] How did the trigger get the IP addresses? Is this also possible
in the inter-technology/inter-domain case? If so, is CAR discovery
then still necessary? Or in other words, isn't your magic trigger
with the IP addresses of places the network wants me to go not exactly 
the list of possible GAARs from a network point of view? Though it is
still not clear to me how this trigger is provided.

 > 
 > Also, could you please say what conclusion you are referring to.

[KEM] I'm referring to the discussion about mobile-centric vs network-centric
approaches related to Steve's presentation. I believe there was a
consensus on mobile-centric, which favours a CAR discovery solution where the
MN is involved and takes the decisions.

[DOT] Steve's presentation has already had a large influence on the requirements 
discussion regarding the involvement of the MN, which has been emphasized in the 
requirements. However, concluding now further from his presentation that the WG is 
in favour regarding certain network-centric (what is that exactly BTW?) or mobile-centric 
approaches does not put the WG in the position it is supposed to be. More precisely, believing 
in consensus doesn't make it a consensus. I cannot remember that there was a consensus call 
during the meeting or after. There was explicitly a question whether to let go the network 
case, which was only supported by three hands. There was also a comment from Steve's side 
that "There are times when information from the ARs might help the mobile node make a better 
decision.  I wasn't advocating killing this work, but it just needs to fit into a basic model.".
Let us simply see whether network assistance (if that's what you mean with network-centric)
solutions would fly under the constraint of the current requirements (which emphasizes
MN's role in this process). 

Regards,



Dirk

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