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Joined: Jul 2004
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Thanks for the clarification. So if the long run is a leg on a switch collisions are not a problem? If I am just running on a hub it is a problem?
Otherwise propagation loss is the only issue?


Greg Fretwell
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Joined: Jul 2004
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If it's between two switches and/or routers, that should be the case. Between a switch and something else it depends on whether the something else is operating in full-duplex or half-duplex mode. Since you can't always tell what you've got (and folks may change stuff around after you leave), I'd say it's best to just follow the spec.

[This message has been edited by SolarPowered (edited 04-22-2005).]

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I think we will all agree if you are selling this installation it should be spec compliant.


Greg Fretwell
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SolarPowered;

Thanks for posting the CSMA/CD information!

Scott35


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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True, 100m is the 'maximum', but ideally you'd have 10m of that reserved-- 5m at the head between the patch panel and network equip, and 5m between the work outlet (user end) and PC (etc).

Joined: Jan 2003
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Quote
Ever seen a CAT5 or CAT5e cable spliced - using normal Wirenuts (little Blues or Little Grays), and there is no data loss situation?

LOL errr maybe. [Linked Image]

I am just a hack when it comes to this stuff.

We where remodeling a large dept store while it was open and 'owned' maintaining all systems.

The demo guys would work nights and end up cutting the POS cabling. It was not Cat 5 but some strange two pair twisted shielded solid hard to work with stuff.

Anyway we had good luck repairing these lines with small grays.

One day we even connected two registers to one home run. As far as we know it work fine.

Well it lit the 'communicating' light on the register and we did not here any complaints from the store people.

Do not worry by the end of the job we had pulled all new POS cable and professionals came in and terminated it. [Linked Image]

Bob


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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You could use wirenuts or pink ladies on a CAT5 and probably get away with it. Just remember to keep the twists in each pair maintained as long as you can and to make a "Y" at the connections with the wirenuts pointed in opposite directions to avoid as much cross talk as possible. It would get you through the weekend but they may not be getting the full speed on the connection.
A slow connection is better than no connection at all when you have a store full of customers.
In real life I can't see why a carefully made splice shouldn't go full speed but I would schedule a proper fix.


Greg Fretwell
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BTW Bob that sounds like Token Ring cable you were working with. It really only goes 16mz so you can get away with a lot. If it does a step down it will be running at 4mz and that will darn near run on Romex or thermostat wire. We were running baseband LANs on telco "silver satin" desk set cords at Burger King until we got the right patch cords.


Greg Fretwell
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Quote

It was not Cat 5 but some strange two pair twisted shielded solid hard to work with stuff.

Ya, this sounds like "IBM - Type 1" Cable.

It's "STP" (Shielded Twisted Pair), with two #20-#22 solid twisted pairs, shielded by foil and an Aluminum/tinned Copper braid - all covered by a black PVC jacket.

Like Greg said, this was most likely used on an IBM Token Ring LAN (Local Area Network).

Also mentioned, was the speed of the Ring possibly reducing to 4 MBPS, from 16 MBPS.
That most likely happened, and the POS users on that "Ring" (or out of that MSAU) did not even notice the difference.

I dealt with a lot of Token Ring LANs at Banks, which were of the IBM System 4700 Architecture.
Teller Stations were simply Terminals ("Dumb Terminals" to be exact), which were driven from the 4701 / 4702 / 4705 Controller.
If a teller Station's Terminal changed speed, no one would even notice - mostly because the workload (Data) was so very basic!

As to the Wirenut splices on the Ethernet; there was one location where the Pairs were not twisted, and another location where the Pairs were twisted about 1 twist in +/- 2 inches.
Looked like they stripped back an 8" section of jacket, then untwisted the pairs to make up the splices - but the pairs naturally re-twisted during the make-up work.

These Stations weren't doing anything that could be considered "Power Use", only Logon and pull Templates off the Server, then save things at the end of the sessions.

Don't even know if they (the users at the Workstations) really needed to Logon at all!
They may already had the Template Files on their Machines, and as far as file saves, this may have been done daily / weekly by Administrators, or an automatic archive application!

The reason I mention this (as many of you that deal with Office Workers know), is the Workstation users simply - by default - Logon to the LAN before doing anything... and I mean ANYTHING!!!

The funniest things to hear, when for some reason Server Access is unavailable are:

* The Network is down, so I cannot:
  • Work on the file(s) I saved yesterday to my machine,
  • Send the document I am looking at right now, to the Printer next to me (local printer),
  • End this game of Solitaire,
  • Do anything!


As annoying as things may become in this part of the field, I really miss it a lot!
Actually, I miss all the stuff I was involved with, "back in the day!" (prior to 2004).
Now, I rarely deal with anything more than "simple LAN work", and certainly nothing with the complexity of the "Active Remodels" on Bank Branches, Loan Centers, and Corporate Campuses!

Makes one feel kind of used up and worthless.

Sorry for the sob story, it's bed time for me!

Scott35


Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!
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Thanks Greg and Scott for the info.

Quote

quote:
--------------------------------------------------------------------------------

It was not Cat 5 but some strange two pair twisted shielded solid hard to work with stuff.

--------------------------------------------------------------------------------

Ya, this sounds like "IBM - Type 1" Cable.

It's "STP" (Shielded Twisted Pair), with two #20-#22 solid twisted pairs, shielded by foil and an Aluminum/tinned Copper braid - all covered by a black PVC jacket.

I don't think so as the cable was red and much thinner overall than the black IBM cables we used to install for another retail customer.

If I remember the IBM 'plugs' where fairly bulky square and black.

This place used another type of connector, I can not describe it as I did not have much to do with it.

The specifications required we leave 15' of the cable in each floor box! (That did not happen even with the large floor boxes we where using (4" round x 6" deep)

The idea was they had many locations where they could place registers through out the store as needed.

Glad most of our customers have gone wireless with portable cash registers.

If it helps the stores where owned by 'May Company' if anyone has worked for them in the past.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
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