----- Original Message ----- From: "Thomas Narten" <[EMAIL PROTECTED]> > > Stepping back for a minute. MAX_RA_DELAY_TIME is .5 seconds. A router > delays a random amount of time between 0 and .5 seconds before > responding. So, on average, .25 seconds. That's not a terribly long > delay. What exactly is the application that can't deal with this kind > of a delay?
Plenty, voice particularly, but it might also kill your TCP transfer. Also saying average .25 sec fudges the issue, 10% of the time it will be greater than .45 sec so users will normally see near the worst case some of the time. > > Then there is more to getting link connectivity than just finding a > router. You may have to generate an address, and then invoke DAD. But > DAD (on an Ethernet) requires a 1 second delay. That's a much bigger > factor than the RS delay. Is this not also an issue? I.e., what is so > critical about getting an immediate RS but that doesn't also have an > issue with some of the other ND/addrconf/DAD constants. Yep it is a big issue, but there are solutions to that as well. Will > addressing the RS delay alone *really* solve the problem here, and if > not, shouldn't we be thinking about the more general problem and > working on finding a solution that deals with all the potential delay > spots? Well the general solution is fast handovers and that is being worked on. But without fast handovers, if you use fast RAs and HMIP and get rid of DAD somehow, the MIPv6 handover can be a few 10s of milliseconds. If you have a fast L2 handover (A big if as it turns out) it is possible that MIPv6 handovers could be really useful even with real time traffic. Richard. > > Thomas > -------------------------------------------------------------------- > 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] --------------------------------------------------------------------
