Re: [apps-discuss] Review of draft-melnikov-smtp-priority-14

ken carlberg <> Tue, 05 June 2012 00:18 UTC

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Cc: Ned Freed <>,,,
Subject: Re: [apps-discuss] Review of draft-melnikov-smtp-priority-14
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On Jun 4, 2012, at 7:14 PM, John C Klensin wrote:

> Yes in principle.  In practice, I've seen one set of communities
> that have repeatedly expressed high levels of demand for
> prioritization.  Those communities are military or ones with
> aspirations to behave like military ones.  For those
> communities, "messages from the General get more delivery
> priority than those from the Lieutenant" have obvious meaning
> and obvious intent.  Moreover, the obvious response, especially
> if someone is a communications officer in that chain of command,
> is to salute and say, "yessir, we will transmit the General's
> message with instructions to process it at higher priority".
> If what happens after that is that this information is passed
> along but no MTA does a thing about it, your observation about a
> second or two takes over, there is a report back to the General
> of complete conformance to his wishes and recognition of his
> exalted status, and everyone is happy.   And, if that trick
> doesn't work, it is always possible to artificially delay  the
> Lieutenant's mail for a while, even if the General has no mail
> in the queue, just to help prove that the General is important.
> Simply dumping the Lieutenant's mail into the queue when it
> arrives while trying to immediately process the General's mail
> for delivery or forwarding would probably be a sufficient
> implementation.   I don't have enough data to claim that
> scenario occurs many times around the world every day, but it
> has got to be close.

so what you describe above is what I've called role-based prioritization.  its the easiest form of prioritization to implement and deploy because its typically associated with a role (sargent, general, etc.) and its generally stagnant and stays associated with a user or device.  several systems for both voice and messaging have been built over the past 50 years or so using this form of prioritization.

another type of system (that I worked on about 25 years ago) is what I refer to as content-based prioritization, where the prioritization is attributed to the content of the message.  So in this case, one could have a case where the user (or a proxy) decides and associates a priority based on the information in the message to be sent.  So in this case, you could have a case where the lowly Sargent trumps the General (kind a cool :-).  And by far, this is the hardest system to build/deploy because one needs to avoid the trap that Dave brought up earlier in that given the freedom, everyone wants to have the highest priority.

In the past few years, some communities have had to rely on the prioritization made available in X.400.  However, these and other communities wish to migrate to SMTP, hence the interest in produce the draft-melnikov-smtp-priority draft.  So what i wanted to point out is that people have indeed worked on these systems and gained experience in the subject area, and we'd like to migrate this to SMTP, as opposed to just relying on proprietary hacks.