If you see
http://abhinavsingh.com/blog/2009/01/behind-the-scenes-how-and-what-xmls-are-exchanged-by-jaxl/
you will get an idea about what you just asked.
In XMPP protocol, client and server can bind to each other for quite a
long period. (until one of the sends a end stream packet or client/
server go down for some reasons)
Jaxl takes care of connecting your app back again to the servers if
connection is reset.
Though you need to take care of how many max such connection can be
opened.
Hope this helps.
Regards,
Abhinav