RE: [Technical Errata Reported] RFC5458 (1746)

"Allison, Art" <> Tue, 07 April 2009 20:23 UTC

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Subject: RE: [Technical Errata Reported] RFC5458 (1746)
Date: Tue, 07 Apr 2009 16:03:20 -0400
Message-ID: <71C9EC0544D1F64D8B7D91EDCC6220200320E6B3@NABSREX027324.NAB.ORG>
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Thread-Topic: [Technical Errata Reported] RFC5458 (1746)
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From: "Allison, Art" <>
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It is simply dead wrong to use TS logical channel in relation to
defining a Transport Stream. 
The errata should delete the term TS logical  channel, not define it as
it only misleads and propagates misunderstanding. 

The term 'TS logical channel'  is not a peer of 'TS multiplex', it is a
component of the TS multiplex. 

A MPEG-2 Transport Stream is a multiplex consisting of a collection of
elementary streams in 188-byte packets each stream having a Packet
IDentifier (PID). 

I attempted to inform authors of RFC4326 of the poor construction at the
time, but the inventors of the term had more time and used it very very
narrowly so it was no longer dead wrong use, at which point my budget to
support this work was exhausted.
I do have time to educate and advocate better resolution of this errata;
but for accurate usage of PID and transport stream see ISO/ITU 13818-1,
not later attempts to 'clarify' those terms by those not expert in
MPEG-2 Systems. 

Art Allison

Director Advanced Engineering, Science and Technology
National Association of Broadcasters
1771 N Street NW
Washington, DC 20036
Phone  202 429 5418 
Fax  202 775 4981

Advocacy  Education  Innovation


|-----Original Message-----
|[] On Behalf Of 
|Sent: Tuesday, April 07, 2009 11:47 AM
|Subject: RE: [Technical Errata Reported] RFC5458 (1746)
| Hi again,
|I suggest to add the the TS Logical Channel definition (taken 
|from RFC 4326). So here is the proposed text:
|TS Logical Channel: Transport Stream Logical Channel. In this 
|document, this term identifies a channel at the MPEG-2 level 
|[ISO-MPEG2]. It exists at level 2 of the ISO/OSI reference 
|model. All packets sent over a TS Logical Channel carry the 
|same PID value (this value is unique within a specific TS 
|Multiplex). The term "Stream" is defined in MPEG-2 [ISO-MPEG2] 
|to describe the content carried by a specific TS Logical 
|Channel (see ULE Stream). Some PID values are reserved (by 
|MPEG-2) for specific signalling. Other standards (e.g., ATSC, 
|DVB) also reserve specific PID values.
|Dr. Haitham S. Cruickshank
|Communications Centre for Communication Systems Research 
|(CCSR) BA Building, Room E11 School of Electronics, Computing 
|and Mathematics University of Surrey, Guildford, UK, GU2 7XH 
|Tel: +44 1483 686007 (indirect 689844)
|Fax: +44 1483 686011
|-----Original Message-----
|From: RFC Errata System []
|Sent: 30 March 2009 08:25
|To: Cruickshank HS Dr (CCSR);; 
|Subject: [Technical Errata Reported] RFC5458 (1746)
|The following errata report has been submitted for RFC5458, "Security
|Requirements for the Unidirectional Lightweight Encapsulation (ULE)
|You may review the report below and at:
|Type: Technical
|Reported by: Alfred Hoenes <>
|Section: 2
|Original Text
|[[ at the bottom of page 5 / top of page 6 ]]
|   TS: Transport Stream [ISO-MPEG2].  A method of transmission at the
|   MPEG-2 layer using TS Packets; it represents Layer 2 of the ISO/OSI
|   reference model.  See also TS Logical Channel and TS Multiplex.
|                              ^^^^^^^^^^^^^^^^^^^^^^^
|<< page break >>
|   TS Multiplex: In this document, ...
|Corrected Text
|   TS: Transport Stream [ISO-MPEG2].  A method of transmission at the
|   MPEG-2 layer using TS Packets; it represents Layer 2 of the ISO/OSI
|   reference model.  See also TS Logical Channel and TS Multiplex.
||  TS Logical Channel: ...   << to be filled in >>
||  ...
|   TS Multiplex: In this document, ...
|The quoted keyword explanation for "TS Logical Channel" 
|is missing in Section 2.
|  Please restore the entry and fill in the missing Corrected Text.
|This errata is currently posted as "Reported". If necessary, please use
|"Reply All" to discuss whether it should be verified or 
|rejected. When a
|decision is reached, the verifying party (IESG) can log in to 
|change the
|status and edit the report, if necessary. 
|RFC5458 (draft-ietf-ipdvb-sec-req-09)
|Title               : Security Requirements for the Unidirectional
|Lightweight Encapsulation (ULE) Protocol
|Publication Date    : March 2009
|Author(s)           : H. Cruickshank, P. Pillai, M. Noisternig, S.
|Category            : INFORMATIONAL
|Source              : IP over DVB
|Area                : Internet
|Stream              : IETF
|Verifying Party     : IESG