One document matched: draft-kumar-avt-v150-registration-02.txt
Differences from draft-kumar-avt-v150-registration-01.txt
Internet Engineering Task Force Rajesh Kumar (Editor)
INTERNET-DRAFT Cisco Systems
draft-kumar-avt-v150-registration-02.txt October 29, 2002
Expires: April 29, 2003
IANA Registration of MIME types and SDP parameters in
proposed ITU Recommendation V.150.1
Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Task
Force (IETF), its areas, and its working groups. Note that other groups
may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet- Drafts as reference material
or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
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Abstract
This document defines a framework for the IANA registration of MIME types and
SDP parameters defined in the ITU V.150.1 recommendation. For SDP parameters,
it does not repeat the details of syntax and semantics found in the ITU
recommendation. For the MIME types, it provides RFC 2048-compliant MIME
definitions which refer to the ITU V.150.1 recommendation for detailed format
description. Until the ITU V.150.1 recommendation is ratified, this document
should be considered work in progress.
1. Introduction.............................................................1
2. Overview of Parameters to be registered....................................2
3. Registration of new SDP parameters.......................................3
3.1 Registration of the 'udpsprt' transport protocol.......................3
3.2 Registration of new SDP attributes.....................................3
4. Registration of new MIME types...........................................3
4.1 Registration of the audio/v150mr MIME type.............................3
4.2 Registration of the audio/v150fw MIME type.............................7
5. Security Considerations..................................................8
6. IANA Considerations......................................................8
7. Acknowledgements.........................................................8
8. References...............................................................9
9. Authors' Addresses......................................................10
1. Introduction
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
There is a need to register ITU V.150.1 parameters with the IANA/ICANN. These
include (i) SDP parameters, and (ii) MIME types. The IANA registration of MIME
subtypes types in the IETF tree requires an RFC approved by the IESG. This
document is meant to fulfill that role.
The ITU V.150.1 recommendation is meant to standardize, in a comprehensive
manner, the encapsulation of modem signals within IP. This includes both modem
passthrough and modem relay operation. The ITU V.150.1 recommendation, which has
been crafted over a period of about two years has been approved for consent
(October 25)and is close to finalization.
This internet draft is initially submitted to the IETF's AVT working group
because of the presence of new MIME definitions. Review by the IETF's MMUSIC
working group is also solicited.
2. Overview of Parameters to be registered
The following parameters defined in ITU V.150.1 recommendation need to be
registered with the IANA:
1. New MIME types: audio/v150mr and audio/v150fw. These indicate media
formats defined, in the ITU V.150.1 recommendation, for use in the modem-
over-IP context. MIME registration applications based on RFC 2048 [4] are
in Section 4. These refer to the ITU V.150.1 recommendation for detailed
format descriptions and semantics.
2. New SDP parameters (Section 3). These include a new transport protocol
(udpsprt, section 3.1) and several new SDP attributes (Section 3.2).
Precise details of their syntax and semantics, found in ITU recommendation
V.150.1, are not repeated.
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3. Registration of new SDP parameters
3.1 Registration of the 'udpsprt' transport protocol
The 'udpsprt' (Simple Packet Relay Transport over UDP) protocol should be
registered as a value of the SDP field "proto", referring to the transport
protocol.
Details of the 'udpsprt' (Simple Packet Relay Transport over UDP) protocol are
found in [1]. This is a reliable protocol that can be used to efficiently
guarantee packet delivery in an IP network that is prone to packet loss.
3.2 Registration of new SDP attributes
New SDP attributes defined in ITU V.150.1 [1] should be registered as values of
the SDP field "att-field". Details of these attributes, listed below, are
found in [1]:
1. sprtparm, a list of parameters qualifying the 'udpsprt' protocol.
2. sprtmap, which dynamically defines a numerical identifier for modem relay
packets.
3. vndpar (vendor parameters), used to declare vendor-specific parameters.
The SDP attribute 'gpmd' (general-purpose media descriptor) is addressed
elsewhere [2]. This attribute is used extensively in ITU V.150.1 systems.
4. Registration of new MIME types
4.1 Registration of the audio/v150mr MIME type
This MIME represents the modem relay packet format as defined in the ITU V.150.1
recommendation. Hence the suffix 'mr' (modem relay).
MIME media type name: audio
MIME subtype name: v150mr
Required parameters:
mr: the type of modem relay, from the set "0" (ITU V.8-compatible
modem relay) and "1" (universal modem relay).
mg: the type of media gateway, from the set "0" (No Transcompression),
"1" (Single Transcompression) and "2" (Double Transcompression.
CDSCselect: Call discrimination mode selection, from the set 1
('audio (RFC 2833)'), 2 ('VBD-preferred'), 3 (Mixed).
mrmods: This parameter lists supported modulation types. These are
listed as one or more comma-separated elements, where each element is
either a single integer or two integers separated by a hyphen. No
white space is allowed. The integers, which designate modulation
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
types are from the set "1" (V.34 duplex), "2" (V.34 Half-duplex), "3"
(V.32bis/V.32), "4" (V.22bis/V.22), "5" (V.17), "6" (V.29 half-
duplex), "7" (V.27 ter), "8" (V.26 ter), "9" (V.26bis), "10" (V.23
duplex), "11" (V.23 half duplex), "12" (V.21), "13" (V.90 analog),
"14" (V.90 digital), "15" (V.91), "16" (V.92 analog) and "17" (V.92
digital).
jmdelay: indicates support of JM delay procedures. Permissible values
are "yes" and "no".
Optional parameters:
versn: Composite representation of the version of the ITU V.150
Recommendation used. Dotted representation, x.y, where the integer 'x'
is the suffix in the number of the controlling Recommendation ('1' for
ITU V.150.1), and the integer 'y' is the version of this
Recommendation ('2' for the version 2 of Recommendation V.150.1). The
default is fixed or configured for the Gateway or endpoint.
Declaration of a value of this parameter implies backward
compatibility with earlier versions (values of 'y') and document
suffixes (values of 'x').
txalgs: This parameter lists supported optional transcompression
algorithms. Not listed is ITU V.42bis, which is mandatory. This list
consists of one or more comma-separated elements. Each element can
either be a single integer or two integers separated by a hyphen. No
white space is allowed. The integers, which designate
transcompression algorithms are from the set "1" (ITU V.44), "2"
(MNP5). If this parameter is omitted, ITU V.44 and MNP5 are not
supported.
V42bNumCodewords: Proposed number of ITU V.42bis code words. This is
an integer in the range 512 û 65535, with a default of 1024.
v42bMaxStringLength: Maximum ITU V.42bis string size, range 6-250. The
default, when omitted, is 32.
v44NumTxCodewords: Proposed number of ITU V.44 transmitter code words.
This is an integer in the range 256 û 65535, with a default of 1024.
v44NumRxCodewords: Proposed number of ITU V.44 receiver code words.
This is an integer in the range 256 û 65535, with a default of 1024.
v44MaxTxStringLength: Maximum ITU V.44 transmitter string size, range
32 û 255. The default, when omitted, is 64.
v44MaxRxStringLength: Maximum ITU V.44 receiver string size, range 32
û 255. The default, when omitted, is 64.
V44LenTxHistory: Proposed size of the V.44 transmitter history, range
512 û 65535. The default, when omitted, is 3072.
V44LenRxHistory: Proposed size of the V.44 receiver history, range 512
û 65535. The default, when omitted, is 3072.
TCXpreference: When two double transcompression (D-TCX) gateways are
connected, this parameter indicates preference for the initial
transcompression mode. Possible values are 1 ('single') and 2
('double'), with 1 as the default.
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
Encoding considerations:
The MIME audio/v150mr uses the 'udpsprt' (Simple Packet Relay
Transport over UDP) reliable transport protocol as defined in the ITU
V.150.1 recommendation. As such, it consists of packets of binary
data.
Security considerations:
The privacy and integrity of the data transmitted via V.150.1 modem
relay must be ensured at the application level by means such as
encryption. The V.150.1 modem relay protocol does not hinder such end-
to-end data protection. Nor does it provide any additional, inbuilt
safeguards that can be used in the absence of end-to-end, application-
level data security. The transcompression and other algorithms used
in V.150.1 modem relay are published in various standards and can be
implemented by a resourceful attacker.
Likewise, V.150.1 modem relay procedures do not address session
authentication, which must be handled end-to-end by client and server
authentication applications. Authentication is out of the scope of a
bearer-level protocol such as V.150.1 modem relay.
Resource usage by a modem relay session may be monitored to prevent
denial of service attacks. The resource utilization of modem relay
sessions does not exhibit such non-uniformity so as to preclude such
resource limiting.
The MIME type contains no executable content that affects sessions or
session legs other than the ones in which the requester is a
participant. For these session legs, executable content in the form of
modem relay control messages is well within the normal prerogatives of
the requester.
Like other encodings with open-ended content, the ITU V.150.1
modem relay format may be abused by hiding data using steganography.
However, due to its more limited context, it is unlikely that it
will be preferred for such misuse vis-a-vis other audio and video
encodings.
Interoperability considerations: Interoperability is limited to endpoints
or gateways that implement the mandatory parts of the ITU V.150.1
recommendation, "Procedures for the end-to-end connection of V-series
DCEs over an IP Network". Backward compatibility will be maintained
between all versions of this recommendation.
Published specification: The ITU V.150.1 specification, approved for
consent on October 25, 2002.
Applications which use this media:
Endpoints and media gateways that interface with V-series modems on
one end, and with an IP network on the other end. In this case, the
on-ramp gateway does not support full modem termination which would
have allowed forwarding via a higher-layer protocol.
Additional information:
1. Magic number(s): N/A
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
2. File extension(s): N/A
3. Macintosh file type code: N/A
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
4.2 Registration of the audio/v150fw MIME type
This MIME represents the format of messages used to define the contextual
framework of information transfer operation as defined in the ITU V.150.1
recommendation. Hence the suffix 'fw' (framework).
MIME media type name: audio
MIME subtype name: v150fw
Required parameters: None.
Optional parameters:
events: The "events" parameter lists the framework event messages
supported by the media gateway or endpoint. Events are listed as one
or more comma-separated elements. Each element can either be a single
integer, or two integers separated by a hyphen. The latter indicates
a range of integers. No white space is allowed in the representation.
The integers, which identify event types are from the set "0" (null),
"1" (initial audio), "2" (voice band data), "3" (modem relay), "4"
(text relay), "5" (fax relay). When omitted, the default is 0-4.
expack: indicates whether explicit framework message acknowledgement
procedures, as defined in the ITU V.150.1 recommendation are enabled
or not. Both sides must enable these procedures in order for them to
be used. Permissible values are "yes" and "no".
Encoding considerations:
Like all other ITU V.150.1 media formats except modem relay, the MIME
audio/v150fw uses the RTP protocol. As such, it consists of packets of
binary data. The RTP payload is defined in the ITU V.150.1
recommendation.
Security considerations:
As with other RTP formats, it is possible to use IPSEC to ensure the
authenticity, integrity and privacy of this media format. Since this
media format is uncompressed, there is no potential conflict between
compression and encryption. Many applications use modem relay between
trusted network equipment and, as such, may forego the use of IPSEC.
When used with equipment in untrusted areas, the impact of the V.150
framework messages is limited to one session. Hence, any exposure from
not encrypting this media format is limited.
Resource usage by V.150 framework messages may be monitored to prevent
denial of service attacks. Since the resource utilization of these
messages is minimal, resource limiting is not precluded.
The MIME type contains no executable content that affects sessions or
session legs other than the ones in which the requester is a
participant. For these session legs, executable content in the form of
V.150 framework messages is well within the normal prerogatives of the
requester.
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
Since the content associated with this MIME type is well-defined and
not open-ended, it is not vulnerable to hiding data using
steganography.
Interoperability considerations: Interoperability is limited to endpoints
or gateways that implement the mandatory parts of the ITU V.150.1
recommendation, "Procedures for the end-to-end connection of V-series
DCEs over an IP Network". Backward compatibility will be maintained
between all versions of this recommendation.
Published specification: The ITU V.150.1 specification, approved for
consent on October 25, 2002.
Applications which use this media:
Endpoints and media gateways that interface with V-series modems on
one end, and with an IP network on the other end. In this case, the
on-ramp gateway does not support full modem termination which would
have allowed forwarding via a higher-layer protocol.
Additional information:
1. Magic number(s): N/A
2. File extension(s): N/A
3. Macintosh file type code: N/A
5. Security Considerations
This document does not impose any security considerations of its own, apart from
the security considerations associated with each MIME type is contains.
Security considerations for SDP parameters defined in this document are
unchanged from RFC 2327 [3].
6. IANA Considerations
The entirety of this document is for IANA review and is limited to such
information as pertinent to the IANA registration of MIME types and SDP
parameters. Details found in ITU Recommendation V.150.1 [1] are not repeated,
except as necessitated by MIME registration rules [4].
7. Acknowledgements
The ITU SG16/Q11 team led by Keith Chu, Rapporteur for the modem-over-IP
question (Q11). This team includes members of the TIA TR.30.1 modem-over-IP
standards group, which was chaired by Les Brown in the past and is currently
chaired by Keith Chu. TIA TR.30.1 reports to the TIA TR.30 organization, which
is chaired by Fred Lucas.
Detailed review of and indispensable contribution towards of the ITU V.150.1 SDP
definition by Flemming Andreasen, Bill Foster and Dave Oran.
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
Jim Renkel who suggested the creation of a 'manyfolks' internet draft leading to
an RFC that highlighted the IANA registration requirements of the ITU V.150.1
recommendation.
8. References
[1] TD-91, Proposed text for ITU V.150.1, Procedures for the end-to-end
connection of V-series DCEs over an IP Network, approved for consent,
Oct 25, 2002.
[2] SDP attribute for qualifying Media Formats with Generic Parameters,
draft-rajeshkumar-mmusic-gpmd-01.txt.
[3] RFC 2327, Session Description Protocol (SDP).
[4] RFC 2048, MIME registration procedures.
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
9. Authors' Addresses
Rajesh Kumar
Cisco Systems
170 West Tasman Dr
San Jose, CA 95035, USA
Phone: +1 408 527 0811
E-mail: rkumar@cisco.com
Jim Renkel
The CommWorks Corporation, a 3COM company
3800 Golf
Rolling Meadows, IL 60008, USA
Phone: +1 847 262 2539
E-mail: james_renkel@commworks.com
Michael Nicholas
The CommWorks Corporation, a 3Com Company
3800 Golf
Rolling Meadows, IL 60008, USA
Phone: +1 847 262 2673
E-mail: Michael_Nicholas@3com.com
Fred Lucas, Chair TIA TR-30
FAL Associates
3421 Buttonwood Court
Reisterstown, MD 21136-4401, USA
Phone: +1 410 239 0248
E-mail: fred.lucas@ieee.org
Keith Chu
TIA TR-30.1 (MoIP) chair
Conexant Systems
4311 Jamboree Road
Newport Beach, CA 92660, USA
Phone: +1 949 579 4121
E-mail: keith.chu@mindspeed.com
Herb Wildfeuer
Cisco Systems, Inc.
150 Castilian Drive
Goleta, CA 93117, USA
Phone: +1 805 961 3620
Email: hwildfeu@cisco.com
Paul E. Jones
Cisco Systems, Inc.
7025 Kit Creek Road
RTP, NC 27709, USA
Phone: +1 919 392 6948
E-mail: paulej@packetizer.com
Adrian Zakrzewski
Texas Instruments, Inc
Kumar et al September 2002 Page 10
IANA Registration of ITU V.150.1 MIMEs and SDP parameters
20450 Century Blvd
Germantown, MD 20874, USA
Phone: +1 301 515 6636
E-mail: azakrzewski@ti.com
Frank Chen
Conexant Systems
4311 Jamboree Road
Newport Beach, CA 92660, USA
Phone: +1 949 579 3296
E-mail: frank.chen@mindspeed.com
Mehryar Garakani
Cisco Systems
150 Castilian Drive
Goleta, CA 93117, USA
Phone: +1 805 961 3640
E-mail: mgarakan@cisco.com
Alex Urquizo
Cisco Systems
1414 Massachusetts Ave.
Boxborough, MA 01719, USA
Phone: +1 978 936 0172
E-mail: aurquizo@cisco.com
Nate Melhorn
Cisco Systems
1414 Massachusetts Ave.
Boxborough, MA 01719, USA
Phone: +1 978 936 0144
E-mail: nmelhorn@cisco.com
Ken Jones
Lucent Technologies
Phone: +1 603 362 5949
E-mail: kdjones1@lucent.com
Daniel DeLiberato
Cisco Systems
1414 Massachusetts Ave.
Boxborough, MA 01719, USA
Phone: +1 978 936 0111
E-mail: ddeliber@cisco.com
Hisham Abdelhamid
Cisco Systems
170 West Tasman Dr
San Jose, CA 95035, USA
Phone: +1 408 525 6940
E-mail: hisham@cisco.com
Mohamed Mostafa
Cisco Systems
170 West Tasman Dr
San Jose, CA 95035, USA
Phone: +1 408 525 2378
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IANA Registration of ITU V.150.1 MIMEs and SDP parameters
E-mail: mmostafa@cisco.com
John Malone,
LAKE Datacomms,
Greenhills Rd,
Dublin 24, Ireland.
Phone: +353 1 403 1000
E-mail: john.malone@lakecommunications.com
Other members of TIA TR.30.1 whose names have been inadvertently omitted.
These will be added in a future revision. Please inform the editor of such
omissions.
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