Re: [AVTCORE] Technical - Re: [Editorial Errata Reported] RFC7273 (4450)

[Kevin Gross <[e-mail]>]

The authors have done some research on this issue and have determined that
all current implementations that signal IEEE 1588-2008 reference clock use
the notation from the examples, not the ABNF notation. We would like to
consider an alternate means of resolving the inconsistency in the RFC in a
manner consistent with existing implementations.

Change:

   ; PTP domain allowed number range: 0-127 (IEEE 1588-2008)
   ptp-domain-nmbr = "domain-nmbr=" ptp-domain-dgts
   ptp-domain-dgts = ptp-domain-n1 / ptp-domain-n2 / ptp-domain-n3
   ptp-domain-n1   = DIGIT             ; 0-9
   ptp-domain-n2   = POS-DIGIT DIGIT   ; 10-99
   ptp-domain-n3   = ("10"/"11") DIGIT ; 100-119
                   / "12" %x30-37      ; 120-127
To this:

   ; PTP domain allowed number range: 0-127 (IEEE 1588-2008)
   ptp-domain-nmbr = ":" ptp-domain-dgts
   ptp-domain-dgts = ptp-domain-n1 / ptp-domain-n2 / ptp-domain-n3
   ptp-domain-n1   = DIGIT             ; 0-9
   ptp-domain-n2   = POS-DIGIT DIGIT   ; 10-99
   ptp-domain-n3   = ("10"/"11") DIGIT ; 100-119
                   / "12" %x30-37      ; 120-127

For consistency, if we take this route we may also want to change:

   ; PTP domain allowed characters: 0x21-0x7E (IEEE 1588-2002)
   ptp-domain-name = "domain-name=" 1*16ptp-domain-char
   ptp-domain-char = %x21-7E

To this:

   ; PTP domain allowed characters: 0x21-0x7E (IEEE 1588-2002)
   ptp-domain-name = ":" 1*16ptp-domain-char
   ptp-domain-char = %x21-7E

The authors are aware of no implementations that signal a IEEE 1588-2002
reference clock.

Any comments from the group on the preferred way to address this?

Kevin Gross - AVA Networks

On Tue, Aug 18, 2015 at 11:36 AM, <[e-mail]> wrote:

> FYI, the type of this erratum has been changed to Technical because it is
> not "a spelling, grammar, punctuation, or syntax error that does not affect
> the technical meaning".
>
> Thank you.
> RFC Editor/ar
>
> On Aug 18, 2015, at 7:49 AM, RFC Errata System <[e-mail]>
> wrote:
>
> The following errata report has been submitted for RFC7273,
> "RTP Clock Source Signalling".
>
> --------------------------------------
> You may review the report below and at:
> http://www.rfc-editor.org/errata_search.php?rfc=7273&eid=4450
>
> --------------------------------------
> Type: Editorial
> Reported by: Kevin Gross <[e-mail]>
>
> Section: 5.5
>
> Original Text
> -------------
> 5.5.  Examples
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 239.0.0.2/255
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/8
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:0
> a=mediaclk:offset=963214424
>
> Figure 6: Media clock directly referenced to IEEE 1588-2008
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 239.0.0.2/255
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/44100/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:0
> a=mediaclk:offset=963214424 rate=1000/1001
>
> Figure 7: "Oddball" sample rate directly refernced to IEEE 1588-2008
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 224.2.228.230/32
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:0
> a=mediaclk:rtp=IN IP4 239.0.0.1 5004 00:60:2b:20:12:if
>
> Figure 8: Stream media clock derived from another RTP multicast
> stream
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 224.2.228.230/32
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:0
> a=mediaclk:IEEE1722=38-D6-6D-8E-D2-78-13-2F
>
> Figure 9: Stream media clock derived from another RTP multicast
> stream
>
>
> Corrected Text
> --------------
> 5.5.  Examples
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 239.0.0.2/255
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/8
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:domain-nmbr=0
> a=mediaclk:offset=963214424
>
> Figure 6: Media clock directly referenced to IEEE 1588-2008
>
> Figure 7 shows an example SDP description 2 channels of 24-bit, 44056
> kHz NTSC "pull-down" media clock derived directly from an IEEE 1588-
> 2008 reference clock
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 239.0.0.2/255
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/44100/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:domain-nmbr=0
> a=mediaclk:offset=963214424 rate=1000/1001
>
> Figure 7: "Oddball" sample rate directly refernced to IEEE 1588-2008
>
> Figure 8 shows the same 48 kHz audio transmission from Figure 6 with
> media clock derived from another RTP multicast stream.  The stream
> providing the media clock must use the same reference clock as this
> stream that references it.
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 224.2.228.230/32
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:domain-nmbr=0
> a=mediaclk:rtp=IN IP4 239.0.0.1 5004 00:60:2b:20:12:if
>
> Figure 8: Stream media clock derived from another RTP multicast
> stream
>
> Figure 9 shows the same 48 kHz audio transmission from Figure 6 with
> media clock derived from an IEEE 1722 AVB stream.  The stream
> providing the media clock must be synchronized with the IEEE 1588-
> 2008 reference clock used by this stream.
>
> v=0
> o=- 1311738121 1311738121 IN IP4 192.168.1.1
> c=IN IP4 224.2.228.230/32
> s=
> t=0 0
> m=audio 5004 RTP/AVP 96
> a=rtpmap:96 L24/48000/2
> a=sendonly
> a=ts-refclk:ptp=IEEE1588-2008:39-A7-94-FF-FE-07-CB-D0:domain-nmbr=0
> a=mediaclk:IEEE1722=38-D6-6D-8E-D2-78-13-2F
>
> Figure 9: Stream media clock derived from another RTP multicast
> stream
>
>
> Notes
> -----
> There is an inconsistency between ABNF in section 4.8 and examples in
> section 5.5. It would be cleaner to correct the examples and that is what
> is proposed above. There is evidence, however, that current implementations
> are working to what is shown in the examples, not according to the ABNF
> specification.
>
> Instructions:
> -------------
> This erratum 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.
>
> --------------------------------------
> RFC7273 (draft-ietf-avtcore-clksrc-11)
> --------------------------------------
> Title               : RTP Clock Source Signalling
> Publication Date    : June 2014
> Author(s)           : A. Williams, K. Gross, R. van Brandenburg, H.
> Stokking
> Category            : PROPOSED STANDARD
> Source              : Audio/Video Transport Core Maintenance RAI
> Area                : Real-time Applications and Infrastructure
> Stream              : IETF
> Verifying Party     : IESG
>