RFC 1528 (rfc1528) - Page 3 of 12

Principles of Operation for the TPC

RFC 1528        Remote Printing -- Technical Procedures     October 1993


   Note that the mailbox syntax is purposefully restricted in the
   interests of pragmatism.  To paraphrase RFC 822, an atom is defined
   as:

      atom    = 1*atomchar

      atomchar=  
                / 
                / "!" / "#" / "$" / "%" / "&" / "'" / "*" / "+"
                / "-" / "/" / "=" / "?" / "^" / "_" / "`" / "{"
                / "|" / "}" / "~"

   Finally, note that some Internet mail software (especially gateways
   from outside the Internet) impose stringent limitations on the size
   of a mailbox-string.  Thus, originating user agents should take care
   in limiting the local-part to no more than 70 or so characters.

2.2 Routing

   The message is routed in exactly the same fashion as all other
   electronic mail, i.e., using the MX algorithm [2].  Since a remote
   printer server might be able to access many printers, the wildcarding
   facilities of the DNS [3,4] are used accordingly.  For example, if a
   remote printer server residing at "dbc.mtview.ca.us" was willing to
   access any printer with a telephone number prefix of

      +1 415 968

   then this resource record might be present

      *.8.6.9.5.1.4.1.tpc.int.    IN MX 10 dbc.mtview.ca.us.

   Naturally, if several remote printer servers were willing to access
   any printer in that prefix, multiple MX resource records would be
   present.

   It should be noted that the presence of a wildcard RR which matches a
   remote printer server's address does not imply that the corresponding
   telephone number is valid, or, if valid, that a G3-facsimile device
   is connected at the phone number.

3. Procedure

   When information is to be remotely printed, the user application
   constructs an RFC 822 message, containing a "Message-ID" field.





Malamud & Rose