[jdev] Communicate between two client instances of the same ID

[Kevin Smith]

On Wed, Sep 3, 2008 at 4:04 AM, Peter Saint-Andre <stpeter at stpeter.im> wrote:
>> I think delivered and delivered once would be good enough for me.
>> If not delivered for any reason, I'd like to be notified about it
>> so that I'll resend it.
> Message receipts (XEP-0184) probably give you what you want, then.

No, it doesn't - we /really/ need to stop saying that 184 gives us
reliable delivery, because it doesn't - it gives us consensual
delivery auditing, or something similar, and that's not the same at
all. 198 is pretty close to reliable delivery for most sane
definitions, but 184 is a very long way off.

Given that responding to the receipt requests is optional,  how do you
cope when you send a message but don't receive a receipt? Resend it
once? Twice? To guarantee delivery, you have to keep sending it until
you get a receipt, and infinite deliveries will take a very long time!
Compare to 198, where the stanzas are always acked per-hop, and you
know that your message will eventually reach its destination. If you
want to have a chance of knowing when it reached, use 184 as well, but
184 on its own isn't what we want for reliable delivery.

/K