Re: failure detection

[Paul Jakma <paul@clubi.ie>]

On Thu, 18 Aug 2005, Paul Jakma wrote:

> - reachability detection itself is unidirectional
>
>  (iljitsch's draft mentions "unidirectional", i know, but wrt
>   outside unidirectional issues. I'm proposing the reachability
>   mechanism itself be unidirectional in nature. Two unidirectional
>   paths == bi-directional :) )

I'd should explain this better:

- the protocol would be to implement "I can hear you", rather than
  "We can both hear each other" (as, eg, some other path-state
  protocols do - like OSPF Hello)

- As an optimisation, if the other side asks "Can you hear me?", you
  can at least infer "I can hear them" - and hence suppress a probe.

Aside: The address tuples used in each direction could be different

PS: I know all the reachability/probing/ULP-feedback talk is all 
still at exploratory stages. Hope I've not been /too/ presumptive in 
attacking ULP-feedback and n^2 probing (ie, attacking these when 
they're only being /considered/, rather than decided on. Just trying 
to nip these two particular ideas in the bud - at least for anything 
other than appendix 'implemention note' type material).

regards,
--
Paul Jakma	paul@clubi.ie	paul@jakma.org	Key ID: 64A2FF6A
Fortune:
I can't live the button-down life like you.  I want it all!  The
terrifying lows, the dizzying highs, the creamy middles!

		-- Homer Simpson
		   Lisa's Rival