RE: 1xx Clarification

If I understand correctly you are interested in 1xx responses appearing within the context of a tcp connection to a HTTP server but outside of  the context of a HTTP request.  If this is correct, I don't see how this will work through a proxy since proxies generally only maintain a connection to the end server for the duration of the request.  Even if the proxy maintains a persistent connection to the server, the connection may only be allocated to a specific client for the duration of a HTTP request.  So in your scenario, going through a proxy I think the sequence would be the following:

User Establishes Connection to Proxy
User sends GET to Proxy
	Proxy Establishes connection to Server
		Server sends 1xx Response to Proxy
	Proxy sends 1xx response to client
	Proxy sends GET to Server
		Server sends second 1xx Response to Proxy
	Proxy sends second 1xx response to client
		Server Sends 200 Response to Proxy
	Proxy sends 200 response to client
		Server sends third 1xx Response to Proxy
	Proxy sends third 1xx response to client
	Proxy closes server connection or "assigns" it to another "client"
		(note that this could happen before the 3rd 1xx response is received)
User Closes Connection to Proxy

so the first 1xx response makes it through, but not outside of the request context.  The second 1xx response works as expected, and the 3rd may or may not make it to the client based on a race condition of when the proxy closes or "reuses" the server connection.

-Doug Crow	

Received on Tuesday, 15 April 1997 11:07:05 UTC