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
