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-
-
- Minutes of the June 21
- SMTP extensions working group.
-
- Attendees
- ---------
-
- Phill Gross pgross@nis.ans.net
- Peter Svanberg psu@nada.kth.se
- Byungnam Chung bnchung.sokri.etra.re.kr
- Bob Kummerfeld bob@ca.pn.oz.au
- Jonny Eriksson bygg@sunet.se
- Jan Michael Rynning jmr@nada.kth.se
- Keld Simonsen keld.simonsen@dkuug.dk
- Greg Vaudreuil gvaudre@nri.reston.va.us
-
- Agenda
- ------
-
- 1) 8 Bit Transport
-
- - Overview of current status
-
- - Review of current proposals
- o Negotiated 8 bit support
- o Unnegotiated 8 bit support
- o Use of 7 bit transport with encoding
-
- - Discussion: Which is the preferred proposal?
-
- 2) Mail Enclave Issues
-
- - Local use of non-standard practices: Real problem or not?
- o Non-standard or non-support of transfer encodings
- o Local use of non-standard character sets
-
- - Define Enclaves
- o Administratively limited?
- o Universal mesh of capabilities?
-
- Minutes
- -------
-
- 1) 8 Bit Transport Issues
-
- Much discussion has occured both on the mailing list and in private
- with the chairman calling into queston the conclusions the smtpext
- working group reached during the St. Louis IETF in March 91. This
- issue was raised at this Copenhagen meeting to reconsider or reaffirm
- the conclusions the working group at that earlier meeting. There
- continue to be two credible proposals for transition to 8 bit
- transport. Th first is a proposal to redefine the SMTP protocol to
- standardize the existing practice sending 8 bit mail over standard
- SMTP channels. The second is a proposal send 8 bit textual data after
- negotiating that capability.
-
- The working group review the two proposals and came to the
- following understandings about the proposals. A third "proposal", do
- nothing, was evaluated as well.
-
- a) Redefine SMTP to pass 8 bit data.
-
- The proposal stems from the existing practice of sending 8 bit data
- between SMTP implementations without negotiation or confirmation of
- the capabilities of the receiver.
-
- Benefits
- --------
-
- - It works (Mostly)
- - Easy modification to existing code to gain functionality
- - Currently deployed by several vendors, and tested extensively in
- current mail environments.
-
- Costs
- -----
-
- - There is no assurance that the message was delivered as intended.
- - Use of C1 codespace may be compromised.
- - Not functionally compatible with many current SMTP
- implementations.
-
- Discussion
- ----------
- - The extensions have been extensively tested in a "friendly"environment
- where character sets sent have not used C1 codespace for graphic
- characters, nor have multi-byte characters been sent.
- - Some unpredictable behavior has been noted.
- - The costs are continuing, they never go away.
-
-
- b) Negotiate the sending of 8 bit data
-
- Benefits
- --------
-
- - Backwards compatible with current conforment implementations.
- - Failure is detectable, and recovery by encoding and resending is
- possible
-
- Costs
- -----
-
- - Not compatible with some (much?) current deployed software
- - Failure recovery after negative negotiation potentially complex
- - Code changes are more complex
-
- Discussion
- ----------
-
- - The costs of the transition are one time, and will fade away with time.
-
- c) Send no 8 bit data
-
- Benefits
- --------
-
- - The hassle of upgrading current transport is unneeded
- - All functionality is supported through encoding
-
- Costs
- -----
- - Encoding required additional resources including computer time as well
- as communications bandwidth
- - Local users may use 8 bit transport anyway.
-
- Discussion
- ----------
-
- - The technical analysis of this issue is but a small part in the problem.
- There is a strong feeling, almost religion,among site administrators and
- many "users" that encoding data that is easily transportable of the
- network infrastructure is wasteful, inelegant, and just plain wrong.
-
-
- d) Conclusions
-
- The attendees of this meeting reaffirmed the working group
- consensus that standard for the transmission of 8 bit characters
- without negotiation has costs which were too in terms of expected mail
- performance to be acceptable. The main points underscoring this
- conclusion was the inability to "know" the transaction was successful,
- and the effective loss of the ability to use C1 codespace in future
- character sets intended to be transportable over SMTP. While it was
- noted that much experience has been gathered with current
- implementations using un-negotiated 8 bit mail, it was understood that
- this experience was gathered in a relatively homogeneous environment
- with friendly character sets. Problems were expected by the working
- groups in general application in the Internet and in sending
- characters sets like IBM PC codepages which use C1 codespace.
-
- 2) Enclave Issues
-
-
- The working group felt that the concept of enclaves was not something
- that had to be defined. Specifically, the idea that enhanced
- capabilities should be confined to a administrative or geographical
- region was seen as being too restrictive. The attendees preferred to
- maintain the end to end model of electronic mail, rather than
- formalize the concept of autonomous mail domains.
-
-