[Standards-JIG] In order delivery for xep-0047 ?
justin-keyword-jabber.093179 at affinix.com
Thu Dec 7 19:45:13 UTC 2006
On Thursday 07 December 2006 8:19 am, Mridul wrote:
> Matthias Wimmer wrote:
> > If you are binding a XMPP stream on a transport protocol, that does
> > not guarantee in-order delivery by itself, your binding would have to
> > ensure the reordering.
> I think the assumption here is that in order processing will immediately
> result in in order delivery - which is a simplistic scenario.
> Anyway, the point is - since xmpp does not mandate in order delivery : I
> am not sure why 47 is trying to mandate it - especially since seq number
> can be used for message re-ordering in case of out of sync delivery.
Except that XMPP *does* mandate in-order delivery. If it is unclear in the
RFC, then it needs to be fixed, since I believe this was always the intent of
the protocol. I think the only reason the document doesn't explicitly
say "in-order delivery" is because this would be redundant in the context of
a single TCP stream. Now that we realize we might have non-TCP bindings, or
multiple TCP streams (s2s), some additional clarification is needed.
However, I don't see in-order delivery between each jid pair to be a threat
Regarding IBB: XMPP guarantees stanza order, but it does not guarantee stanza
delivery to occur. Therefore, a sequence number is needed to detect a hole
in the transfer (missing packet). The sequence number is not used for any
kind of reordering.
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