[jdev] XEP-0199 (XMPP Ping) to test reliability
Yann Leboulanger
asterix at lagaule.org
Mon Jan 21 14:19:37 CST 2008
Dave Cridland wrote:
> On Mon Jan 21 18:52:54 2008, Yann Leboulanger wrote:
>> In gajim we send whitespace ping if we haven't received or sent
>> anything in the past 55 seconds (cause some nat server close
>> connection if nothing happen in a minute)
>> But whitespace ping are not enough, so replacing it with xmpp-ping
>> with the same time would be nice.
>>
>>
> Mhh. Okay. Whitespace pings aren't enough to tell if the connection is
> actively able to send and receive packets. XEP-0199 tells you not only
> that, but it also tells you whether the thing you're pinging is willing
> and able to respond.
>
> Both have a use, although for c2s links, XEP-0198 is rather more powerful.
>
> Don't confuse those use-cases, because whether or not you use XEP-0199
> to test c2s connectivity, whitespace pings are still lighter, and
> perfect for keeping recalcitrant NATs in line.
>
> XEP-0199 is particularly useful when you're expecting a response, but
> don't seem to be getting anything.
>
>
>> about the time for answer, are some network connection or server so
>> slow that it can reply only 20 seconds later? I have no feedback on
>> that, but isn't 5 or 10 seconds enough?
>
> HF radio links would need much more, whereas a DSL link would need less.
>
> A good rule of thumb might be 10 times the normal RTT. (Which you can
> detirmine by the usual response to XEP-0199 pings).
>
> IMHO, a nice UI would simply note that the latency seemed tremendously
> high, and offer to reconnect, rather than kill the session - as Michal
> pointed out, the user often knows what the situation is.
>
> Dave.
Ha yes I didn't know XEP 198 has a ping section. But we don't get an
answer, at least with my ejabberd. And in this case an answer is
usefulle to know if server is still alive. So I think XEP 199 is better.
--
Yann
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