| Author |
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James Knott
Guest
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 Posted:
Sun Feb 20, 2005 7:26 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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Robert Redelmeier wrote:
| Quote: | Gerard Bok <bok118@zonnet.nl> wrote:
What I am saying is, that for Wifi frequencies a Pringle
can probably outperforms any thinnet cable :-)
An interesting statement.
How many dB of loss are there in closely coupled transmitting
& receiving antennae ? 100 dB in antenna efficiency? Add to
that the inverse-square losses of ~400ft of air (52db?)
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Then again, using a cable probably has fewer calories. ;-) |
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James Knott
Guest
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| Posted:
Sun Feb 20, 2005 7:30 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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William P.N. Smith wrote:
| Quote: | What, no attenuators for the OP's 10 feet of cable? Hunh, I'd at
least have kept an open mind, but maybe that's just me.
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I don't recall any mention of 10' of cable. He did mention 10 Mb. |
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Guest
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| Posted:
Sun Feb 20, 2005 8:12 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | I don't recall any mention of 10' of cable.
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Exactly my point. Without knowledge of the cable length and
characteristics, the whole discussion was degenerating into "We don't
know nothing, but it can't possibly work over 165 meters of the lowest
quality Thinnet cable, we think...." |
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sphealey
Guest
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| Posted:
Mon Feb 21, 2005 2:29 am Post subject:
Re: Anything faster I can run on Thinnet? |
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| Quote: | back in about '91 DEC made an FDDI over coax converter.
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I have been been able to find some mention of that technology, but no
part numbers or product line names. Would anyone happen to remember
what they were called and/or a part number?
Thanks.
Sorry about leaving the length out on my original post; I thought I had
included it. There is no usable specification information that I can
find on the cable.
sPh |
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Al Dykes
Guest
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| Posted:
Mon Feb 21, 2005 5:07 am Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <1108934978.001018.114540@o13g2000cwo.googlegroups.com>,
sphealey <sphealey@worldnet.att.net> wrote:
| Quote: | back in about '91 DEC made an FDDI over coax converter.
I have been been able to find some mention of that technology, but no
part numbers or product line names. Would anyone happen to remember
what they were called and/or a part number?
Thanks.
Sorry about leaving the length out on my original post; I thought I had
included it. There is no usable specification information that I can
find on the cable.
sPh
|
Wait a moment while I whip out my DEC Network Buyer's Guide 1992-1993
(several hundred pages) Here it is, Chapter 3.
You have the DECbridge 500/600/700 (FDDI ring to 10mb 802.3 ethernet)
and the DECconcentrator 500 (FDDI ring to FDDI devices)
You'd need two cables because FDDI requires a ring, or better
yet 4 for a dual ring.
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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Rich Seifert
Guest
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| Posted:
Mon Feb 21, 2005 6:10 am Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <1108934978.001018.114540@o13g2000cwo.googlegroups.com>,
"sphealey" <sphealey@worldnet.att.net> wrote:
| Quote: | back in about '91 DEC made an FDDI over coax converter.
I have been been able to find some mention of that technology, but no
part numbers or product line names. Would anyone happen to remember
what they were called and/or a part number?
|
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
--
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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Gerard Bok
Guest
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| Posted:
Mon Feb 21, 2005 4:48 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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On Sun, 20 Feb 2005 17:10:33 -0800, Rich Seifert
<usenet@richseifert.com.invalid> wrote:
| Quote: | In article <1108934978.001018.114540@o13g2000cwo.googlegroups.com>,
"sphealey" <sphealey@worldnet.att.net> wrote:
back in about '91 DEC made an FDDI over coax converter.
I have been been able to find some mention of that technology, but no
part numbers or product line names. Would anyone happen to remember
what they were called and/or a part number?
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
|
But the crucial question hete is: would this product run more
than 10 Mbps over 'thinnet coax' ? :-)
--
Kind regards,
Gerard Bok |
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Al Dykes
Guest
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| Posted:
Mon Feb 21, 2005 6:26 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <4219c80b.541526@News.Individual.NET>,
Gerard Bok <bok118@zonnet.nl> wrote:
| Quote: | On Sun, 20 Feb 2005 17:10:33 -0800, Rich Seifert
usenet@richseifert.com.invalid> wrote:
In article <1108934978.001018.114540@o13g2000cwo.googlegroups.com>,
"sphealey" <sphealey@worldnet.att.net> wrote:
back in about '91 DEC made an FDDI over coax converter.
I have been been able to find some mention of that technology, but no
part numbers or product line names. Would anyone happen to remember
what they were called and/or a part number?
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
But the crucial question hete is: would this product run more
than 10 Mbps over 'thinnet coax' ? :-)
--
Kind regards,
Gerard Bok
|
The FDDI-ethernet version had 10mb ethernet interfaces so you'd
get no speed increase on any single system.
The FDDI ring to fddi computer version requires a FDDI card for one of
yoru systems (at both ends). It's possible that the standards are
good enough that you could get any PCI fddi card and hook it up.
And, as I said before, FDDI requires a ring so you'd need two TW
cables to form one.
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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sphealey
Guest
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| Posted:
Mon Feb 21, 2005 7:50 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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| Quote: | Wait a moment while I whip out my DEC Network
Buyer's Guide 1992-1993 (several hundred
pages) Here it is, Chapter 3.
|
I don't know which is worse: that you have that in your possession, or
that I envy you for having it when I don't! Must .... hide ......
sickness ... from .... spouse. Must .... hide .......
sPh |
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Al Dykes
Guest
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| Posted:
Mon Feb 21, 2005 8:04 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <1108997416.774125.309870@z14g2000cwz.googlegroups.com>,
sphealey <sphealey@worldnet.att.net> wrote:
| Quote: | Wait a moment while I whip out my DEC Network
Buyer's Guide 1992-1993 (several hundred
pages) Here it is, Chapter 3.
I don't know which is worse: that you have that in your possession, or
that I envy you for having it when I don't! Must .... hide ......
sickness ... from .... spouse. Must .... hide .......
sPh
|
Everything shows up on ebay, eventually.
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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Rich Seifert
Guest
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| Posted:
Mon Feb 21, 2005 8:43 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <4219c80b.541526@News.Individual.NET>,
bok118@zonnet.nl (Gerard Bok) wrote:
| Quote: | On Sun, 20 Feb 2005 17:10:33 -0800, Rich Seifert
usenet@richseifert.com.invalid> wrote:
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
But the crucial question hete is: would this product run more
than 10 Mbps over 'thinnet coax' ? :-)
|
Since the impedance of 'thinnet coax' is identical to that of thick
Ethernet coax, clearly any system that will run on one will run on the
other; the only question is the reduction in length for acceptable
levels of operation.
(Remember, other than the connector used to attach to the medium, a
'thinnet' transceiver is *IDENTICAL* to a thick Ethernet transceiver.)
--
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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Guest
|
| Posted:
Mon Feb 21, 2005 8:45 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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Do you have any phone lines between the buildings?
Long range ethernet operates at up to 15Mbps full duplex
(well 15 is more than 10). Speed though depends on the
*cabling* and *distance*.
Have a quick look at
http://www.cisco.com/nobel/initiative/docs/NNI_CP_02.pdf
Then look up the costs.
Why do you need more than 10Mbps?
If you for example have an old network using repeaters
you might be able to get by with installing a switch
or router to control the traffic, eliminate unwanted
broadcasts, whatever. Maybe you can use data compression?
You can get laser links that will do the job however
they are prone to interruption by birds, rain, have
a read, just google on [laser ethernet] for example.
In the UK non-omni antenna are illegal for 802.xyz (I
think anyway) however there may well be commecial
solutions available in the US.
google [802.11 directional antenna]
http://www.hyperlinktech.com/web/antennas_2400_out_directional.php
There you go! I would thing a couple of these would
sort you out.
http://www.fab-corp.com/
HAve amplifiers too - I would go for antennas first.
I am sure that one of the previous contributors to this
thread can quickly work out which one of these beasts
would do the job for you. I might be able to attempt
it but it would take me hours or days and I don't
know yet how much confidence I might have in the result:)
Wireless can be affected by weather (maybe other posters
can contribute?) so I wouldn't go for the mimimum possible
solution.
You can always keep the coax link on 10M as a backup. |
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Gerard Bok
Guest
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| Posted:
Mon Feb 21, 2005 9:30 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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On Mon, 21 Feb 2005 07:43:07 -0800, Rich Seifert
<usenet@richseifert.com.invalid> wrote:
| Quote: | In article <4219c80b.541526@News.Individual.NET>,
bok118@zonnet.nl (Gerard Bok) wrote:
On Sun, 20 Feb 2005 17:10:33 -0800, Rich Seifert
usenet@richseifert.com.invalid> wrote:
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
But the crucial question hete is: would this product run more
than 10 Mbps over 'thinnet coax' ? :-)
Since the impedance of 'thinnet coax' is identical to that of thick
Ethernet coax, clearly any system that will run on one will run on the
other; the only question is the reduction in length for acceptable
levels of operation.
|
Sorry, but I have to disagree here.
Basically, both cables should at least comply to the same specs.
That, I agree to.
But from a practical point of view:
A typical thicknet cable is Belden 9880.
6.9 dB per 100 feet attenuation at 1000 MHz, 11.5 dB at 2.5 GHz
(So it would be suitable for 'Wifi')
A typical thinnet cable is Belden 9907
14.8 dB per 100 feet at 1000 MHz, 2.5 GHz not even specified :-)
As you see: size does matter, at least if you want to run
something else over an existing cable.
--
Kind regards,
Gerard Bok |
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Al Dykes
Guest
|
| Posted:
Mon Feb 21, 2005 9:49 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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In article <421a0b11.3798725@News.Individual.NET>,
Gerard Bok <bok118@zonnet.nl> wrote:
| Quote: | On Mon, 21 Feb 2005 07:43:07 -0800, Rich Seifert
usenet@richseifert.com.invalid> wrote:
In article <4219c80b.541526@News.Individual.NET>,
bok118@zonnet.nl (Gerard Bok) wrote:
On Sun, 20 Feb 2005 17:10:33 -0800, Rich Seifert
usenet@richseifert.com.invalid> wrote:
There was an early proposal for a version of FDDI that ran over coax; it
was referred to as LDDI. DEC also made a proprietary product (pre-FDDI)
that ran on thick Ethernet coaxial cable; it was used for the back-end
connection in the original VAXCluster product.
But the crucial question hete is: would this product run more
than 10 Mbps over 'thinnet coax' ? :-)
Since the impedance of 'thinnet coax' is identical to that of thick
Ethernet coax, clearly any system that will run on one will run on the
other; the only question is the reduction in length for acceptable
levels of operation.
Sorry, but I have to disagree here.
Basically, both cables should at least comply to the same specs.
That, I agree to.
But from a practical point of view:
A typical thicknet cable is Belden 9880.
6.9 dB per 100 feet attenuation at 1000 MHz, 11.5 dB at 2.5 GHz
(So it would be suitable for 'Wifi')
A typical thinnet cable is Belden 9907
14.8 dB per 100 feet at 1000 MHz, 2.5 GHz not even specified :-)
As you see: size does matter, at least if you want to run
something else over an existing cable.
--
Kind regards,
Gerard Bok
|
The spec ifor TW is primarily impedance and mechanical dimensions
which just have to match the BNC connector used on each end (N for
thickwire cable).
The loss specification is either "don't care" for small networks or
"lower the better" if you are pushing the distance limits. These
belden part numbers are used for applications other than Thinwire and
designers need to know loss numbers. I don't imagine there is a big
market for TW, or thickwire, these days.
You are not talking about pulling new wire. You've gotta use what
you've got which, ISTR you've said has no identifying info on it. I
hope it didn't come from Rat Shack.
Your only hope to use your cable, ISTM, is to buy a pair of "g" wifi
APs that have screw-on antenna connectors and coax adapters
(SMC-to-BNC, or whatever) to connect to the cable and go for it. It
might work. This is not big bucks and if the test fails you can sell
the APs to someone. I guess you set them up as a mesh bridge.
IMO, on a good day, "g" will be modestly faster than 10mb ethernet,
measured by actual thruput.
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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James Knott
Guest
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| Posted:
Mon Feb 21, 2005 10:15 pm Post subject:
Re: Anything faster I can run on Thinnet? |
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Gerard Bok wrote:
| Quote: | Since the impedance of 'thinnet coax' is identical to that of thick
Ethernet coax, clearly any system that will run on one will run on the
other; the only question is the reduction in length for acceptable
levels of operation.
Sorry, but I have to disagree here.
Basically, both cables should at least comply to the same specs.
That, I agree to.
But from a practical point of view:
A typical thicknet cable is Belden 9880.
6.9 dB per 100 feet attenuation at 1000 MHz, 11.5 dB at 2.5 GHz
(So it would be suitable for 'Wifi')
A typical thinnet cable is Belden 9907
14.8 dB per 100 feet at 1000 MHz, 2.5 GHz not even specified :-)
As you see: size does matter, at least if you want to run
something else over an existing cable.
|
1) Last I heard, ethernet over coax does not use frequencies anywhere near
2.5 GHz.
b) I guess you missed the point "the only question is the reduction in
length for acceptable levels of operation". |
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