What does the X stand for in TX- FX

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

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

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <373odbF53nm17U1@individual.net>,
"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.


--
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

 

[Michael]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"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).

Michael
(remove filter from email address)
http://www.ethernetinthefirstmile.com

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

In article <420ce95f$0$23753$ba620e4c@news.skynet.be>,
"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.


--
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

 

[Michael]

Archived from groups: comp.dcom.lans.ethernet (More info?)

"Rich Seifert" worte:
> "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

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

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...
> 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
>
>
>

 

[Guest]

Archived from groups: comp.dcom.lans.ethernet (More info?)

Hello Rich,

RHS> 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.

I would like a modem that runs as fast as SCSI ...over a
domestic analogue telephone line.

- Andy Ball