[Standards] s2s and gracelessly broken streams

Matthias Wimmer m at tthias.eu
Mon Apr 2 22:42:17 UTC 2007

Hi Tony!

Tony Finch schrieb:
>> I think this is best answered in the form of a question: How well do you
>> think SMTP would scale if it held open connections for every domain that
>> is in your address book?
> At my site our central email relays (used by about 30,000 people)
> connected to 5,500 different IP addresses in the last day, so it's
> less of a problem than you might expect.

Your mailserver connected to the servers you exchanged messages with, 
not with all the servers of your users in your address book.

But no matter how many s2s connections we have, we must use the 
resources we have even on a server as economical as possible. That we 
currently have a less economical protocol in terms of needed open 
connections on the c2s side is no reason to make s2s less economical.

Due to my experience servers that went down is only the cause for a very 
small fraction of wrong presences. Our main problem still seems to be, 
that even the user's server has a wrong impression of this user's 
presence (i.e. servers that do not detect that a user is not online 
anymore). We now have XEP-0199 that allows a server to probe if a client 
is still online. We should first see how much the problem of stale 
presences is improved if servers XEP-0199-pinging idle clients get more 
widely deployed, before we start tweaking less important factors.


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