SONET and SDH

Michelot

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Jun 4, 2006, 4:23:35 PM6/4/06

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Bonjour Huub,

SONET has been defined before SDH.

For G.707, the date of the issue 1.0 is 1988-11-25
Have you please the first publication date for GR-253-CORE? perhaps
1984

Thanks for that,
Best regards
Michelot

Bert Klaps

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Jun 5, 2006, 8:28:46 AM6/5/06

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Hi Michelot,

Michelot wrote:
> SONET has been defined before SDH.

That depends on what you call SONET ;-)
SONET as we know it know was developped together with SDH in
the 1986-1988 timeframe. As such SONET is present in ITU-T SDH
as a subset - the differences mainly in nomenclature and some
overhead processing.
Effort on SONET however had started some years before,
but that version of SONET was different from what we know now:
it had a different bit rate, a different frame format, bit
interleaving,
different mapping, ...

See
http://media.wiley.com/product_data/excerpt/8X/07803116/078031168X.pdf
for a history of early SONET standardisation.

> For G.707, the date of the issue 1.0 is 1988-11-25
> Have you please the first publication date for GR-253-CORE? perhaps
> 1984

Ahum, the first GR-253-CORE issue was December 1994.
I don't know if there were earlier Telcordia/BellCore documents,
with different document id, though.

SONET was actually defined by ANSI T1X1 (now ATIS OPTXS)
in its T1.105 series of standards.
The first T1.105 also dates from 1988 - that should be a few
months earlier than G.707.

Regards,
Bert

Huub van Helvoort

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Jun 5, 2006, 8:10:05 AM6/5/06

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Bonjour Michelot,

You wrote:

> SONET has been defined before SDH.

Are you responding to my answer in the IETF PWE3 mailing list? ;-)

SDH and SONET as they are currently deployed are defined almost at
the same time: end of 1988.

> For G.707, the date of the issue 1.0 is 1988-11-25

Issue 1 of ANSI T1.105 where SONET is defined is also from 1988.

Please read the article I referred to in my answer on the PWE3 list:
http://www1.ietf.org/mail-archive/web/pwe3/current/msg08260.html

> Have you please the first publication date for GR-253-CORE? perhaps
> 1984

No, Belcore (later Telcordia) always uses T1.105 as the base for
defining GR-253-Core, so it is always later.
In fact the first issue of GR-253-Core is form 1994.

> Thanks for that,

You're welcome.

Kind regards, Huub.

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Michelot

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Jun 6, 2006, 11:46:21 AM6/6/06

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Bonjour Bert,

> http://media.wiley.com/product_data/excerpt/8X/07803116/078031168X.pdf
> for a history of early SONET standardisation.

Thanks for that link. It appears very interresting.

> Ahum, the first GR-253-CORE issue was December 1994.

Yes, I read that but I was not sure of the rightness. In my head, I
thought that T1.105 was published after the first issue of GR-253-CORE,
and it is not correct.

Best regards,
Michelot

Michelot

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Jun 6, 2006, 12:03:19 PM6/6/06

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Bonjour Huub,

> Are you responding to my answer in the IETF PWE3 mailing list? ;-)

It's just a coincidence beyong the borders. I don't know Sasha, and
perhaps I would have.

> No, Belcore (later Telcordia) always uses T1.105 as the base for
> defining GR-253-Core, so it is always later.
> In fact the first issue of GR-253-Core is form 1994.

I thought it was the opposite. So, I correct my judgement and have to
read the text from media.willey.com.

Best regards,
Michelot