Subject: [drinks] Transport requirements in the protocol draft

From: Otmar Lendl <[email-masked]>
Date: Mon, 22 Nov 2010 11:27:36 +0100

One quick feedback to draft-ietf-drinks-spprov-03:

------
4.9. Request Acknowledgement

   Data transported in the SPPP protocol is likely crucial for the
   operation of the communication network that is being provisioned.

   Failed transactions can lead to situations where a subset of public
   identifiers (or even SSPs) might not be reachable, or situations
   where the provisioning state of the network is inconsistent.

   Therefore, a transport protocol for SPPP MUST provide a Response for
   each Request, so that a Client can identify whether a Request
   succeeded or failed.
------

There is no protocol which can guarantee that Registry and Client both know
for sure that the transaction went through and that the other side also
knows this.

(cf. 2/3 phase commit, Two generals' problem, ...)

On other words, there is little a transport protocol can resolve if it has
to deal with sudden loss of connectivity.

otmar
-- 
// Otmar Lendl <[email-masked]>, T: +43 1 5056416 - 33, F: - 933 //