According to the XEP: http://www.xmpp.org/extensions/xep-0124.html#poll "If the client sends two consecutive empty new requests (i.e. requests with incremented rid attributes, not repeat requests) within a period shorter than the number of seconds specified by the 'polling' attribute (the shortest allowable polling interval) in the session creation response, and if the connection manager's response to the first request contained no stanzas, then upon reception of the second request the connection manager SHOULD terminate the HTTP session and return a 'policy-violation' terminal binding error to the client." A polling interval should only be enforced when the last poll's response contained no stanzas. http://www.igniterealtime.org/community/thread/30671