[jdev] About "No Operation"

[BreezeChan]

Dear All,

Is there have any command like "NOP" in ftp protocol for XMPP?
There have  a proxy server between  my jabber client & server,if no communication between the server and client in ten seconds,
the proxy server will drop the conneciton. So,i hv to let the client send somthing to server every 9 seconds. Does XMPP 
have some command just for keep connecion ?

B RGDS,
Breeze