| Author |
Message |
Justin Champion
Guest
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 Posted:
Fri Feb 11, 2005 5:57 pm Post subject:
What does the X stand for in TX- FX |
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Hello can anyone tell me what the X indicates in a TX or FX cable.
Thanks,
Justin.
--
----------------------------------------------------------------------------
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"There's no point in being grown up if you can't be childish sometimes"
Fourth Doctor Who(Tom Baker)
Doctor Who Web Site www.doctorwho.hopto.org |
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Rich Seifert
Guest
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| Posted:
Fri Feb 11, 2005 9:49 pm Post subject:
Re: What does the X stand for in TX- FX |
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In article <373odbF53nm17U1@individual.net>,
"Justin Champion" <justin@champion.fsbusiness.co.uk> wrote:
| Quote: | Hello can anyone tell me what the X indicates in a TX or FX cable.
|
It doesn't "stand for" anything. When we were developing the 100 Mb/s
Ethernet standard, a proposal was initially presented for an encoding
scheme that supported both twisted pair and fiber. To facilitate
discussion, it was called "100BASE-X", where the "X" was a placeholder
for whatever medium would ultimately be used. The symbolism stuck and we
kept the "X" designation to indicate the use of 4B/5B block encoding;
-TX meant that coding on twisted pair, and -FX meant that encoding used
on fiber.
--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX
Send replies to: usenet at richseifert dot com |
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Michael
Guest
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| Posted:
Fri Feb 11, 2005 10:20 pm Post subject:
Re: What does the X stand for in TX- FX |
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"Rich Seifert" wrote:
| Quote: | "Justin Champion" <justin@champion.fsbusiness.co.uk> wrote:
Hello can anyone tell me what the X indicates in a TX or FX cable.
It doesn't "stand for" anything. When we were developing the 100 Mb/s
Ethernet standard, a proposal was initially presented for an encoding
scheme that supported both twisted pair and fiber. To facilitate
discussion, it was called "100BASE-X", where the "X" was a placeholder
for whatever medium would ultimately be used. The symbolism stuck and we
kept the "X" designation to indicate the use of 4B/5B block encoding;
-TX meant that coding on twisted pair, and -FX meant that encoding used
on fiber.
|
So it's a coincidence then that the ANSI standards which these port types
are based on, also have an X in their name? If I'm not mistaken, the PCS of
100BASE-X is based on the X3.263 standard (FDDI), and the PCS of 1000BASE-X
is based on the X3.230 standard (Fibre Channel).
Michael
(remove filter from email address)
http://www.ethernetinthefirstmile.com |
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Rich Seifert
Guest
|
| Posted:
Fri Feb 11, 2005 11:47 pm Post subject:
Re: What does the X stand for in TX- FX |
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In article <420ce95f$0$23753$ba620e4c@news.skynet.be>,
"Michael" <usenet@filter.ethernetinthefirstmile.com> wrote:
| Quote: | "Rich Seifert" wrote:
"Justin Champion" <justin@champion.fsbusiness.co.uk> wrote:
Hello can anyone tell me what the X indicates in a TX or FX cable.
It doesn't "stand for" anything. When we were developing the 100 Mb/s
Ethernet standard, a proposal was initially presented for an encoding
scheme that supported both twisted pair and fiber. To facilitate
discussion, it was called "100BASE-X", where the "X" was a placeholder
for whatever medium would ultimately be used. The symbolism stuck and we
kept the "X" designation to indicate the use of 4B/5B block encoding;
-TX meant that coding on twisted pair, and -FX meant that encoding used
on fiber.
So it's a coincidence then that the ANSI standards which these port types
are based on, also have an X in their name? If I'm not mistaken, the PCS of
100BASE-X is based on the X3.263 standard (FDDI), and the PCS of 1000BASE-X
is based on the X3.230 standard (Fibre Channel).
|
Total coincidence. Remember, ALL of the ANSI computer technology
standards have an "X3" designation, from X3.1 (Synchronous Modem
Signaling Rate standard) to X3.332 (SCSI-3) and everything in between.
--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX
Send replies to: usenet at richseifert dot com |
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|
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Michael
Guest
|
| Posted:
Sat Feb 12, 2005 4:32 pm Post subject:
Re: What does the X stand for in TX- FX |
|
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"Rich Seifert" worte:
| Quote: | "Michael" <usenet@filter.ethernetinthefirstmile.com> wrote:
"Rich Seifert" wrote:
"Justin Champion" <justin@champion.fsbusiness.co.uk> wrote:
Hello can anyone tell me what the X indicates in a TX or FX cable.
It doesn't "stand for" anything. When we were developing the 100 Mb/s
Ethernet standard, a proposal was initially presented for an encoding
scheme that supported both twisted pair and fiber. To facilitate
discussion, it was called "100BASE-X", where the "X" was a placeholder
for whatever medium would ultimately be used. The symbolism stuck and
we
kept the "X" designation to indicate the use of 4B/5B block encoding;
-TX meant that coding on twisted pair, and -FX meant that encoding
used
on fiber.
So it's a coincidence then that the ANSI standards which these port
types
are based on, also have an X in their name? If I'm not mistaken, the PCS
of
100BASE-X is based on the X3.263 standard (FDDI), and the PCS of
1000BASE-X
is based on the X3.230 standard (Fibre Channel).
Total coincidence. Remember, ALL of the ANSI computer technology
standards have an "X3" designation, from X3.1 (Synchronous Modem
Signaling Rate standard) to X3.332 (SCSI-3) and everything in between.
|
Maybe so, but not all the Ethernet port types reference ANSI X-series
standards! ;-) Anyway, thanks for clearing up this little mistery about
Ethernet.
Note also that 10PASS-TS references American National Standard T1.424, but
the T's in both names have nothing to with each other either!
Michael
(remove filter from email address)
http://www.ethernetinthefirstmile.com |
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Justin Champion
Guest
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| Posted:
Sun Feb 13, 2005 12:02 am Post subject:
Re: What does the X stand for in TX- FX |
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|
Thank you this helps
Justin.
--
----------------------------------------------------------------------------
--------
"There's no point in being grown up if you can't be childish sometimes"
Fourth Doctor Who(Tom Baker)
Doctor Who Web Site www.doctorwho.hopto.org
"Justin Champion" <justin@champion.fsbusiness.co.uk> wrote in message
news:373odbF53nm17U1@individual.net...
| Quote: | Hello can anyone tell me what the X indicates in a TX or FX cable.
Thanks,
Justin.
--
--------------------------------------------------------------------------
--
--------
"There's no point in being grown up if you can't be childish sometimes"
Fourth Doctor Who(Tom Baker)
Doctor Who Web Site www.doctorwho.hopto.org
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Andy Ball
Guest
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| Posted:
Thu Mar 10, 2005 1:14 pm Post subject:
Re: What does the X stand for in TX- FX |
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Hello Rich,
RHS> Remember, ALL of the ANSI computer technology
| Quote: | standards have an "X3" designation, from X3.1
(Synchronous Modem Signaling Rate standard) to X3.332
(SCSI-3) and everything in between.
|
I would like a modem that runs as fast as SCSI ...over a
domestic analogue telephone line. :-)
- Andy Ball |
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