SOAP:Lite Client - server message passing

[pj]

Hi,
sends a file
SiteA: client --------------------------------> SiteB: server
<--------------------------------
sends a file

I want to implement something like above using SOAP:Lite. I know a
client can send a file to a server, but can server send a file to a
client? if so, how can this be done? All I know is the return
"message" to send a string message.

I was planning to do something like the following. Each sites has SOAP
client and server.

sends a file
SiteA: client --------------------------------> SiteB: server
server<-------------------------------- client
sends a file

But I am wondering if it can be done with SiteA:client and
SiteB:server.
thanks in advance.