kit@gateway.mitre.ORG (03/16/91)
Dear Jacob Palme, Thank you for your notes on the X.400 development group meeting of Feb 1991. I note in particular the text on delivery notices from X.400 to fax (which I have excerpted, at the bottom of this message). I am surprised and pleased to see this, since I have raised similar issues at the NIST OIW X.400 SIG two years ago (and had them rejected by the SIG). The concensus at the SIG at the time was that the DN went back based upon the MTA's actions, not on the UA's actions. The concensus was that even if the UA or AU could not decode the message contents at all there would still have been a DN sent back to the X.400 originator by the MTA prior to the UA processing of the message. In a previous job I had, there was a real market requirement to be able to determine that the message was really deliverable end-to-end, which was a problem for fax and telex recipients. The users did not want to be billed for an international telex message (for example) if that message did not actually get sent. For example, if the user typed an incorrect telex recipient address, the X.400 message resulted in a delivery notice (DN) at the point where the MTA delivered the message to the Access Unit (AU), which caused the sender to be billed for the telex message despite the telex message not actually being delivered to the end telex recipeint. We had done a modification to our AU software so that it delayed the confirmation of the MessageDelivery operation until after the AU had determined that the message was deliverable to the end telex recipient; therefore, we could count on a DN to mean that it did get sent to the telex recipient, and an NDN meant that the AU had triggered the MTA to do an NDN because the message was not deliverable to the end telex recipient. I think that the above description is consistent with what you were describing for the case of sending from X.400 to Fax. I just hope you can generalize it, rather than just limiting it to Fax traffic. Kit Lueder. > From: Jacob Palme QZ <JPALME@qz.qz.se> > Subject: Report from X.400 development group meeting February 1991 > Date: 13 Mar 91 04:45:42 GMT > To: mhsnews@qz.qz.se > > Notifications when sending from X.400 to Fax > -------------------------------------------- > > There was a discussion on whether a delivery > notification should be sent, for a message which is > transferred from X.400 to facsimile, either: > > (a) At the delivery to the so-called access unit, i.e. > from X.400 to the Telefacsimile transfer system. > > (b) At the delivery to the recipient fax machine. > > We decided on (b). However, future work may include > adding new variants of delivery notifications, including > notifications sent at delivery from X.400 to a fax > transfer system. > > We also decided that receipt notification are not > meaningful when delivering from X.400 to fax. >