[Standards] Proposed XMPP Extension: Roster Versioning

Magnus Henoch mange at freemail.hu
Sun Mar 23 15:47:49 UTC 2008

Dave Cridland <dave at cridland.net> writes:

>> But that's neither here nor there. The question is whether:
>> (1) acking an occasional roster push from the server to the client
>> (where BTW the server *does* know your full JID) is a serious
>> problem
>> that we need to solve because it wastes large amounts of bandwidth
> It's not the bandwidth, it's the additional transmission I'm more
> concerned with. For every <iq/> stanza, there's an addition TCP data
> packet, and therefore there'll be a further ACK - both of which will
> cost power.
> The alternative is that we quietly explain to people that they needn't
> bother replying to the <iq/> push, which I really don't like.  I'm
> pretty sure that the mobile developers won't want to reply to  every
> roster push, anyway.

I think this is a problem that has already been solved in practice - if
the server doesn't include an id attribute in the roster push (despite
what RFC 3920 says), the client won't send a reply, being liberal about
what it accepts.  At least, that's what jabber.el does after I
encountered that problem.  (And I promptly reported a bug against that
server--I think it was jabberd2--and it was fixed ☺)

JID: legoscia at jabber.cd.chalmers.se

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