Hello Tony,
It is possible to have nice handoffs even with break-before-make, as long as "break" is not too lengthy. If the determination about the destination network is available in time, completing DAD before switching is a good idea -- whether or not the handoff is "break-before-make". This is under discussion within the seamoby working group. We have a draft about it, and an optimistic DAD scheme. When my head rises more than an millimeter above water, I'll read the draft in the Subject: line (glub, glub). Regards, Charlie P. Tony Hain wrote: > > True, but the term 'hand-off' implies a make-before-break process, else > the MN is just establishing itself on a new link. Given it has the > opportunity to be aware of multiple links, it can decide when to switch. > I am arguing that it complete DAD 'before' it makes that decision, not > after. > > Tony > > > -----Original Message----- > > From: Pekka Savola [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, October 15, 2002 1:32 PM > > To: Tony Hain > > Cc: 'Nick 'Sharkey' Moore'; [EMAIL PROTECTED] > > Subject: RE: Optimistic DAD draft ... > > > > > > On Tue, 15 Oct 2002, Tony Hain wrote: > > > [...] it would seem the prudent thing for a MN to do is > > establish DAD > > > for all candidate prefixes well before it is ready to start using > > > them. [...] > > > > Isn't there a problem with how this could be done, as > > currently specified? > > > > One can't perform DAD before being on the link. > > > > > > -----Original Message----- > > > > From: [EMAIL PROTECTED] > > > > [mailto:[EMAIL PROTECTED]] On Behalf Of Nick > > > > 'Sharkey' Moore > > > > Sent: Monday, October 14, 2002 7:58 PM > > > > To: [EMAIL PROTECTED] > > > > Subject: Optimistic DAD draft ... > > > > > > > > > > > > G'day IPng-ers, > > > > > > > > One of the big issues in getting low-latency > > > > handovers working for IPv6 mobility is the long delay involved in > > > > completing DAD. > > > > > > > > One option is to allow the Mobile Node to communicate > > > > while the address is still Tentative (optimistically assuming > > > > that DAD will succeed), but to adjust its ND / SAA behaviour > > > > in order to minimize disruption in case of an address > > > > conflict (and maintain correct interoperation with > > unmodified nodes). > > > > > > > > We've kicked the idea around a little on mobile-ip, > > > > and I've formalized my thoughts into an internet draft, > > which should > > > > get published soon. In the meantime, you can find it at > > > > <http://www.ctie.monash.edu.au/ipv6/fastho.htm> > > > > (tentatively titled draft-moore-ipv6-optimistic-dad-00). > > > > > > > > I'd be interested in your opinions on the draft, and its > > > > potential suitability for standards track. > > > > > > > > > > > > cheers, > > > > Nick > > > > -- > > > > Nick 'Sharkey' Moore <[EMAIL PROTECTED]> > > > > Research Fellow, CTIE Tel: +61 3 9905 3707 > > > > Monash University, Australia Fax: +61 3 9905 5358 > > > > > > -------------------------------------------------------------------- > > > > 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] > > > > > > -------------------------------------------------------------------- > > > > > > > > > > > > > -------------------------------------------------------------------- > > > 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] > > > -------------------------------------------------------------------- > > > > > > > -- > > Pekka Savola "Tell me of difficulties surmounted, > > Netcore Oy not those you stumble over and fall" > > Systems. Networks. Security. -- Robert Jordan: A Crown of Swords > > > > -------------------------------------------------------------------- > 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] > -------------------------------------------------------------------- -------------------------------------------------------------------- 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] --------------------------------------------------------------------
