A JXTA {@link net.jxta.endpoint.MessageTransport} implementation which which provides client polling and server store-and forward functionality for peers incapable of receiving incoming connections. A virtual transport, the messages are transfered between peers using client initiated connections of some other message transport. @see net.jxta.endpoint.EndpointService @see net.jxta.endpoint.MessageTransport @see net.jxta.endpoint.MessageSender @see net.jxta.endpoint.MessageReceiver @see net.jxta.endpoint.Message @see JXTA Protocols Specification : Standard JXTA Transport Bindings