RFC3362 - Real-time Facsimile (T.38) - image/t38 MIME Sub-type Registration

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　　Network Working Group G. Parsons
Request for Comments: 3362 Nortel Networks
Category: Standards Track August 2002

Real-time Facsimile (T.38) - image/t38
MIME Sub-type Registration

Status of this Memo

This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2002). All Rights Reserved.

Abstract

This document describes the registration of the MIME sub-type
image/t38. The encoding is defined by ITU Recommendation T.38 and is
intended for use as an Session Description Protocol (SDP) media
descriptor.

1. Conventions used in this document

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC2119
[REQ].

2. Overview

This document describes the registration of the MIME sub-type
image/t38. The encoding is defined by [T.38] and is intended for use
as an SDP media descriptor.

3. T.38 Definition

ITU-T Recommendation T.38 [T.38] describes the technical features
necessary to transfer facsimile documents in real-time between two
standard Group 3 facsimile terminals over the Internet or other
networks using IP protocols. The Recommendation allows the use of
either TCP or UDP depending on the service environment.

ITU-T Recommendation T.38 [T.38] Annex D describes system level
requirements and procedures for internet aware facsimile
implementations and internet aware facsimile gateways conforming to
ITU-T T.38 to establish calls with other ITU-T T.38 implementations
using the procedures defined in IETF RFC2543 [SIP-99] and IETF RFC
2327 [SDP].

Note that ITU-T T.38 Recommendation T.38 (04/02) [T.38] is an
aggregation of the original ITU-T Recommendation T.38 (06/98) [T.38-
98] and all of the subsequent Amendments and Corrigendum including
[T.38D-00]. While [T.38] and [T.38D-00] describe SIP procedures per
[SIP-99], the procedures can also be applied to the revised Session
Initiation Protocol specification [SIP].

3.1 image/t38 Usage

Annex D of [T.38] describes that the image/t38 media type is intended
to indicate a T.38 media stream in SDP.

This media type registration is not intended for email usage.

4. IANA Registration

To: ietf-types@iana.org
Subject: Registration of Standard MIME media type image/t38

MIME media type name: image

MIME subtype name: t38

Required parameters: none

Optional parameters: none

Encoding considerations: Binary

Security considerations:

This content denotes a facsimile bit stream that may or
may not be encrypted.

Interoperability considerations :

This MIME media subtype is intended to be used as a
parameter by SDP in SIP call setup for T.38 as described in
ITU-T Rec. T.38 Annex D. Any use of this media type by
email applications is not defined and as a result is not
guaranteed to interoperate with a T.38 stream.

Published specification:

ITU-T Recommendation T.38, 'Procedures for real-time
Group 3 facsimile communication over IP networks', April
2002.

A copy of the T.38 specifications can be found at:

http://www.itu.int/rec/recommendation.asp?type=folders&;
lang=e&parent=T-REC-T.38

Applications which use this media type:

Real-time facsimile (fax)

Additional information:

Magic number(s):
II (little-endian):
MM (big-endian):
File extension(s): .T38
Macintosh File Type Code(s): T38

Person & email address to contact for further information:

Glenn W. Parsons
gparsons@nortelnetworks.com

Intended usage: COMMON

Change controller: Glenn Parsons

5. Security Considerations

Security considerations for this media type are discussed in the MIME
type registration that appears in section 4.

6. References

[REQ] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC2119, March 1997.

[MIME4] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Four: Registration Procedures", BCP
13, RFC2048, November 1996.

[SDP] Handley, M. and V. Jacobson, "SDP: Session Description
Protocol", RFC2327, April 1998.

[SIP] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
A., Peterson, J., Sparks, R., Handley, M. and E. Schooler,
"SIP: Session Initiation Protocol", RFC3261, June 2002.

[SIP-99] Handley, M., Schulzrinne, H., Schooler, E. and J.
Rosenberg, "SIP: Session Initiation Protocol", RFC2543,
March 1999.

[T.38] ITU-T Recommendation T.38, 'Procedures for real-time Group
3 facsimile communication over IP networks', April 2002.

[T.38-98] ITU-T Recommendation T.38, 'Procedures for real-time Group
3 facsimile communication over IP networks', June 1998.

[T.38D-00] ITU-T Recommendation T.38 Amendment 2 Annex D, 'SIP/SDP
Call Establishment Procedures', February 2000.

7. Authors' Address

Glenn W. Parsons
Nortel Networks
P.O. Box 3511, Station C
Ottawa, ON K1Y 4H7
Canada

Phone: +1-613-763-7582
Fax: +1-613-763-2697
EMail: gparsons@nortelnetworks.com

8. Full Copyright Statement

Copyright (C) The Internet Society (2002). All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
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followed, or as required to translate it into languages other than
English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an
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BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
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Acknowledgement

Funding for the RFCEditor function is currently provided by the
Internet Society.

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