Alper E. YEGIN wrote: > ... > We cannot assume all MNs can "anticipate movement". Not all > link-layers > have this capability.
A MN 'can anticipate movement' because that is what it does by definition. What it may not be able to figure out is the candidate list of where it may end up. The fact that some link layer implementations have chosen not to expose knowledge of potential alternatives is possibly due to a lack of requirements to do so. I know the 802.11 implementation I am using is fully aware of the candidate set of layer 1 associations, though it doesn't attempt to bind the IP stack until I select one. It would be easy for it to bind IP to all, but prioritize to the selected one until it was out of range. If it did so, all possible destinations could have run a full DAD in the background, well in advance of the move. Even if the MN implementation chose not to associate with all possible layer 1 neighbors, the ones it does have an association with will also be able to hear a partial list of the candidate set, and could provide that to the MN if the implementation provided a path from the layer 1 receiver to a control plane process. It is true that a standards effort can not assume that all implementations will provide a full spectrum of capability, but it is also true that it MUST NOT assume that ignoring a collision avoidance system will not really do any harm. If people want to be mobile, but a specific link-layer doesn't provide the tools to make that work correctly without problems, the link-layer will fade from the market place. Tony -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
