IPP> Re: NOT - ISSUE 04 in the IPPGET spec [Printer closing o utbound channel connection only]

IPP> Re: NOT - ISSUE 04 in the IPPGET spec [Printer closing o utbound channel connection only]

Carl Kugler kugler at us.ibm.com
Mon Aug 13 15:51:21 EDT 2001


If the TCP server (Printer) closes the connection, it has to keep the
connection around in the TIME_WAIT state for two times max time-to-live,
(four minutes).

     -Carl


>
>-----Original Message-----
>From: Marty Joel [mailto:mjoel at netreon.com]
>Sent: Saturday, August 04, 2001 5:00 AM
>To: ipp at pwg.org
>Subject: Re: IPP> Re: NOT - ISSUE 04 in the IPPGET spec [Printer closing
>outbound channel connection only]
>
>
>
>
>Hi Tom, Ira, et al,
>
>
>Connection closing is a keep-alive issue. Why does it matter who closes
>the connection or when, as long as it is closed correctly (through the TCP
>close handshake)?
>
>
>Marty
>
>
>
>
>
>
>"Hastings, Tom N" <hastings at cp10.es.xerox.com>@pwg.org on 08/03/2001
>05:26:12 PM
>
>
>Sent by: owner-ipp at pwg.org
>
>
>
>To: "ipp (E-mail)" <ipp at pwg.org>
>cc:
>
>
>Subject: IPP> Re: NOT - ISSUE 04 in the IPPGET spec [Printer closing
>      outbound c hannel connection only]
>
>
>
>Ira McDonald was having trouble with his email, so here is his response to
>Carl Kugler comment about the Printer closing the outbound half of the
HTTP
>session only.
>
>
>So OK if the IPPGET spec doesn't mention outbound channel and says just:
>
>
>The Printer in Get-Notifications MUST ALWAYS let the Notification
>Recipient close the connection, unless a long timeout expires at
>the Printer. That timeout needs to be long enough for the client to
>receive
>a response.
>
>
>Tom
>
>
>-----Original Message-----
>From: McDonald, Ira
>Sent: Thursday, August 02, 2001 08:57
>To: Hastings, Tom N; McDonald, Ira
>Subject: RE: FW: IPP> NOT - ISSUE 04 in the IPPGET spec
>
>
>Hi Tom,
>
>
>No - closing the outbound half of the HTTP session and underlying
>TCP connection is failure prone and is not even supported anymore
>by some OS libraries (TCP is the only transport protocol with
>half-connections modelled).
>
>
>The Printer in Get-Notifications should ALWAYS let the Notification
>Recipient close the connection (unless a long timeout expires at
>the Printer).
>
>
>Cheers,
>- Ira
>
>
>-----Original Message-----
>From: Carl Kugler [mailto:kugler at us.ibm.com]
>Sent: Tuesday, July 31, 2001 11:27
>To: Hastings, Tom N
>Cc: Lewis Harry (E-mail); Parra, Hugo (E-mail); Michael Sweet (E-mail);
>Ted Tronson (E-mail)
>Subject: Re: FW: IPP> NOT - ISSUE 04 in the IPPGET spec
>
>
>>ISSUE 04: OK to clarify that a client or a Printer MAY disconnect the
>>underlying transport connect for any operation, including the Event No
>Wait
>>Get-Notifications operation and the Event Wait Get-Notifications
operation
>>when the Printer isn't willing to honor the initial request or reneges in
>a
>>later response?
>
>
>>So a client could keep the connection open for multiple Event No Wait
>>Get-Notifications. Before a Printer disconnects it needs to wait enough
>>time to make sure that any IPP response has had time to get back to the
>>client before disconnecting, otherwise the client might not see the
>>response.
>
>
>Preferably, the Printer should close only the outbound half of the
>connection. The client, reading the final response and getting the close,
>should then close the entire connection.
>
>
>     -Carl
>
>
>
>





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