RE: Identifier/locator recap

["Tony Li" <Tony.Li@procket.com>]

Erik,

|    To me this is a no brainer because I can't see how there
|    can exist a scalable approach to multihoming that doesn't
|    separate identifiers and locators.


Excellent, welcome to the club.

    
|    At some level one could argue that host multi-addressing 
|    is scalable
|    (at the expense of moving complexity to the hosts and 
|    applications).but
|    my concern is that host multi-addressing will more or less have
|    the hosts track with source/destination combinations 
|    (which approximate
|    routing paths at some rough level) work vs. doesn't.


Yes, that's going to happen.


|    To get fast failover this essentially turns into doing 
|    end-to-end "hello"
|    traffic instead of relying on the local hello traffic 
|    performed by the routing
|    protocols. So I think there are severe limitations in 
|    making this scale.
|    (And trying to aggregate this end-to-end "hello" traffic will just
|    cause a reinvention of routing.)


As Iljitsch seemed to hint at, there is no need to add protocol to
do this.  For example, a TCP implementation can simply watch the
RTT, compare it to the sRTT and consider switching locators anytime
it needs to retransmit.

I don't know of a requirement that asks us to react faster than that
timeframe, just that we not drop TCP connections.  So why not use
what's there?

Tony