Ira's proposal, in part, was:
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5.2. Conformance Requirements for IPP Printers
IPP Printers that conform to this specification:
a) SHOULD reject received IPP URLs in "application/ipp" request
bodies (e.g., in the "printer-uri" attribute in a 'Print-Job'
request) that do not conform to the ABNF for IPP URLs specified in
section 4.4 of this document;
b) SHOULD return IPP URLs in "application/ipp" response bodies (e.g.,
in the "job-uri" attribute in a 'Print-Job' response) that do
conform to the ABNF for IPP URLs specified in section 4.4 of this
document;
c) MUST listen for IPP operations on IANA-assigned well-known port
631.
d) MUST NOT listen for IPP operations on any other port, unless
explicitly configured by system administrators or site policies.
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I believe we should change D to "SHOULD NOT." There are existing
implementations whose out-of-box behaviour is to listen on multiple ports
including 631. In addition, future implementations may provide different
classes of service or provide other differentiation based on port number. For
example a "Super IPP" implementation may provide additional functions in
addition to IPP on say port 6310. We should not invalidate (i.e. make
non-compliant) devices whose out-of-box behaviour is to offer IPP services on
other ports as long as they do support 631.
BTW: This was also the opinion of those in attendance at the last face-to-face
meeting.
**********************************************
* Don Wright don at lexmark.com *
* Chair, Printer Working Group *
* Chair, IEEE MSC *
* *
* Director, Strategic & Technical Alliances *
* Lexmark International *
* 740 New Circle Rd *
* Lexington, Ky 40550 *
* 859-232-4808 (phone) 859-232-6740 (fax) *
**********************************************