On Mon, Dec 1, 2008 at 12:53 PM, Yakov Rekhter <[EMAIL PROTECTED]> wrote: > Tony, > >> |Recent postings suggest drop the first packet during map >> |lookup. Oeps!!!! >> |I think first packet delivery is a MUST. >> >> >> The problem is that first packet delivery requires buffering. To quote an >> esteemed colleague: "Buffering bad." ;-) > > This discussion focuses on the implication of dropping or buffering > the first packet of a given flow. But there are cases where other > than the first packet of a given flow would need to be either > buffered or dropped. > > Consider the scenario where an ITR goes down, and as a result *all* > the flows that used to go through that ITR would need to be shifted > to other ITR(s), and other ITR(s) have no mapping info for these/
if the ITR goes down won't the IGP/EGP take care of shifting some/all/most of this traffic away? for the ETR that might be more complex, but for the ITR there is either a backup/neighbor/vrrp-pair or another option (another link) for this traffic to go to, right? (or there SHOULD be, or the customer is in the same problem space as they are in today's internet... their PE device died and has no routes, so no traffic gets passed) > flows. What would these other ITR(s) do with the packets of these > flows as these other ITR(s) are in the process of acquiring mapping I suspect that the same thing that happens today happens tomorrow, packets/flows get dropped. Losing a router isn't a recoverable situation today, if you have no routing info you are SOL. > info ? Would these other ITR(s) buffer all of them until they acquire > the mapping info ? (with link speeds of of several Gb/s that may > be a *lot* to buffer). Or would they drop all of them until they > acquire the mapping info ? (with link speeds of several Gb/s that > may be a *lot* to drop). agreed, this is a bunch of traffic, but it's a problem we have today already. This isn't changed with any proposal going forward, as with APT even you don't necessarily have enough routing info to see the default-mapper at boot-time (depending on deployment scenarios of course). -chris _______________________________________________ rrg mailing list [email protected] https://www.irtf.org/mailman/listinfo/rrg
