Re: [RE] Compatibility with 802 and why the study group is not yet a task force
I second Alexei's comments. That is, the size of the market is inversely
proportional to the complexity of the solution, especially for CE
systems. From recent comments, there is also the perception that we are
proposing a complex Synch-Ethernet solution for applications that don't
need it. I would advise newcomers to go to early RE material, from the
time of the CFI.
Dirceu Cavendish
NEC Labs America
10080 North Wolfe Road Suite SW3-350
Cupertino, CA 95014
Tel: 408-863-6041 Fax: 408-863-6099
-----Original Message-----
From: owner-stds-802-3-re@IEEE.ORG [mailto:owner-stds-802-3-re@IEEE.ORG]
On Behalf Of Alexei Beliaev
Sent: Tuesday, April 12, 2005 2:13 PM
To: STDS-802-3-RE@LISTSERV.IEEE.ORG
Subject: Re: [RE] Compatibility with 802 and why the study group is not
yet a task force
It is good! We agree that accurate time reference is required in the
house infrastructure!
Now let's be careful about what we assume when we speak about live
performances. As for me, it is not about studio installations or
anything very much professional. Professionals usually can afford
expensive solutions, and they certainly can use multiple network cards
in dedicated computers on isolated networks which are managed using
special software. My case of live performance is about our kids playing
music together at home, and I believe that many people would find this
impractical to set up a special room for such activities in their houses
(at least if they had a choice). I also know that there is a very large
number of people who play music at home just for pleasure so it would be
too much if we say that each of them requires a studio. Having a
dedicated computer with dedicated interface for musical applications is
inconvenient but unavoidable in today home music recording/playing. It
is simple, but it can not be cheap, because it is very specific and
constraining.
Regards,
Alexei Beliaev
Gibson Labs
408-313-2665
----- Original Message -----
From: Denis Beaudoin
To: Alexei Beliaev
Cc: STDS-802-3-RE@LISTSERV.IEEE.ORG
Sent: Tuesday, April 12, 2005 12:51 PM
Subject: Re: [RE] Compatibility with 802 and why the study group is
not yet a task force
I don't necessarily agree, a live performance would not be part of the
house infrastructure, but in a studio or reserved room where traffic
from other sources would not be seen and/or be an issue. I know today
when I do live recordings I'm not backing up the PC or watching a video
from the PC at the same time or surfing the internet. If a simple
solution could answer all, then great! But if not, the home studio
market still pays more anyway, put 4 Ethernet ports in the PC one for
the instruments switch, one for the home network and one for each
Speaker. I thinks its still cheaper than the 20 plus 1/4 inch patch
cords I use today!
PS: It solves the delay and QOS issues as well.
I do agree that both the home infrastructure and the live performance
do require an accurate time reference. But now the problem is different,
so the solution can be much cheaper.
Regards Denis
Alexei Beliaev wrote:
Actually, it looks like the message contains a bit of illustration
to existing problems:
- The network delay is never 6% (or any other certain/fixed/bounded
value)
- When it comes to a solution then it would be more convenient to
have one that works for all of mentioned applications (audio listening,
live performances, gaming, video watching, etc.). The are not so
fundamentally different.
Regards,
Alexei Beliaev
Gibson Labs
408-313-2665
----- Original Message -----
From: Solomon, Yoram
To: STDS-802-3-RE@LISTSERV.IEEE.ORG
Sent: Tuesday, April 12, 2005 7:25 AM
Subject: Re: [RE] Compatibility with 802 and why the study group
is not yet a task force
I fully agree. We seem to be focused on the solution before
defining the problem. I would like for us to work on a problem
definition in Austin.
Regards,
Yoram.
------------------------------------------------------------------------
--
From: owner-stds-802-3-re@IEEE.ORG
[mailto:owner-stds-802-3-re@IEEE.ORG] On Behalf Of Beaudoin, Denis
Sent: Tuesday, April 12, 2005 6:42 AM
To: STDS-802-3-RE@LISTSERV.IEEE.ORG
Subject: Re: [RE] Compatibility with 802 and why the study group
is not yet a task force
Two last elements to add to the list that may help RE move
forward.
1) Define the problem! All I hear is how the solution will fix it,
but when I see the latency diagram, the network only consists of less
than 6% of the total delay. Why are we not focusing on the other 94% of
the path delay?
2) Once the problem is defined, break the problem into appropriate
classes like Audio Listening, Video Watching, Live Performances, Gaming,
etc. It may be that the solution for most of the classes is already
here, and the solution for a couple of the classes may need features to
be added in 802.3.
I also agree with Arthur, the RE study group should use the IEEE
RE reflector.
Regards Denis
Arthur Marris wrote:
Second attempt to get this sent to the email list
------------------------------------------------------------------------
From: Arthur Marris
Sent: 11 April 2005 11:53
To: owner-stds-802-3-re@IEEE.ORG
Subject: Compatibility with 802 and why the study group is not
yet a task force
Folks,
On reviewing the Yahoo mailing list archive I saw an email
asking why the compatibility with 802 criterion failed to get the
necessary 75% approval in the 802.3 closing plenary session. In my view
there are two reasons for this:
1) It was stated during the debate in the closing plenary by a
study group member that no changes to the MAC or PHY may be necessary.
If that is the case then what is the point of doing an 802.3 project?
You need to give the 802.3 working group some idea of what it is that
you want to do.
2) You failed to convince 802.1 that what you are proposing is
compatible with their switching specs. The tutorial gave the impression
that the purpose of the task force would be to standardize a mooted
Firewire switch architecture in 802.1. This switch architecture requires
a separate queue for RE traffic and is required to deliver frames at
precise time intervals. Predictably this did not go down well in 802.1
and the 802.3 working group took notice of this.
I also have the following observations to make
i) To see RE through as an 802.3 project you need to engage with
the wider 802.3 working group. Using a Yahoo mailing list rather than
this one does not help. If you want to know why people voted against the
compatibility criterion ask on this mailing list. The vote to set up the
study group was 41 to 7 so there is support for a task force and making
changes to the 802.3 spec for RE. Don't squander this good will.
ii) You need a chair who is experienced in 802.3 policy and
procedures.
iii) You need to come up with a quantitative requirement for
jitter and relative latency and justify it. I saw the figure of 10us
mentioned on the Yahoo mailing list. This is ridiculously tight. An
802.3 voter who is experienced in VOIP pointed out to me that even 1ms
is too tight when you consider that sound only travels one foot in a
millisecond. Once you have this requirement nailed a lot else will fall
into place.
iv) The sort of thing that would make sense for a task force
would be to develop a mechanism for measuring link delay using MAC
control frames so that time stamp information could be accurately
interpreted. This is within the scope of 802.3 and clearly relevant to
what you are trying to achieve with residential Ethernet.
Arthur.
--
Denis Beaudoin DMTS Texas Instruments dbeaudoin@ti.com
972-480-3277
--
Denis Beaudoin DMTS Texas Instruments dbeaudoin@ti.com
972-480-3277