XEP-0199: XMPP Ping support
Most jabber servers, including ejabberd 2.0.0, don't supports this XEP (for ejabberd exists patch). Gajim supports, but some strange. For example, every 10(?) seconds it seng ping to server:
\<iq to="jabber.org" type="get" id="''xxx''">
\<ping xmlns="urn:xmpp:ping" />
\</iq>
And every time server response:
\<iq from='jabber.org' to='''jid''/Gajim' type='error' xml:lang='en' id='''xxx'''>
\<ping xmlns='urn:xmpp:ping'/>
\<error code='501' type='cancel'>
\<feature-not-implemented xmlns='urn:ietf:params:xml:ns:xmpp-stanzas'/>
\</error>
\</iq>
It is extra traffic and for client, and for server. But client can reduce this, if will got information about XEP-0199 support in server via disco ( == http://www.xmpp.org/extensions/xep-0199.html == 5. Discovering Support) Need analyze
\<feature var='urn:xmpp:ping'/>
field in service discovery information response and if server don't support ping, don't send it.