RT> In its current incarnation, IPP relies on HTTP 1.1, which by default
RT> maintains persistent TCP connections between HTTP client and HTTP
RT> server.
RT> With persistent connections a client can make as many requests and
RT> receive as many responses as it wishes prior to the closing the
RT> connection. NOTE: the server or the client may elect to close a
RT> connection so both client and server should be prepared to handle
RT> an unexpected connection close operation.
To expand on that just a little...
Either side may indicate that a connection is closing so that the
close need not be unexpected. The client may send
Connection: close
in a request to indicate that the server should close the connection
after sending the response, or the server may send the same header
in a response to indicate that the connection will be closed after
this response and so may not be used for the next request.
In the absence of the 'Connection: close' header, the connection
should remain open (though if idle it may be closed by either side
after some timeout).
HTTP/1.1 shouldn't maintain lots of connections to the same server
(and there is little or no benefit in doing so as a rule); from the
spec:
Clients that use persistent connections SHOULD limit the number of
simultaneous connections that they maintain to a given server. A
single-user client SHOULD maintain AT MOST 2 connections with any
server or proxy.
-- Scott Lawrence EmWeb Embedded Server <lawrence@agranat.com> Agranat Systems, Inc. Engineering http://www.agranat.com/