E1and RJ48(C|X) cabling

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Hello,

I'm currently using RJ48C cables to connect an aculab card (Prosody
PCI) to a PBX to make calls, etc. via this. Unfortunately I've had
several problems with this, as the setup seems very fragile with
regards to physical strees as minor pushes, shortcircuiting cables,
etc has caused quite a lot of havoc. I was wondering whether there was
anything to do about this, and have a few questions

1) The wikipedia page (http://en.wikipedia.org/wiki/RJ48 ) mentions
that

   "RJ48X is a variation of RJ48C that contains shorting blocks in the
jack so that a loopback is created for troubleshooting when unplugged
by connecting pins 1 and 4, and 2 and 5."

Would a RJ48X cable give earlier/more distinct warnings when state was
inspected through appropriate software (aculab callmanager)?

2) Is there a variation of Cat 5  cabling/RJ45 connectors that makes
it easier to fabricate the cables?

3) Where to buy the cables? A google search only turns up one company
in the U.S. Is the standard known by some other name in Europe? Or
does everyone make these cables themselves?

I'm amazed at how easy the setup breaks (say compated to standard
ethernet), so in general I'm wondering how other people handle this?

Thanks,

Mads

Re: E1and RJ48(C|X) cabling
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Maybe you have some really bad cables in general? Copper is
copper. I've installed literally hundreds and hundreds of T1 circuits
with basic voice-grade/cat3/cat5 cabling. Most patching was done with
bog-standard ethernet patch cords. Cross connects were punched down on
stock 66 or 110 blocks. I've used ABAM cabling a few dozen times, but
got tired of sourcing it and dropped using it, and installations just
kept working fine after a dozen years on voice-grade cabling.

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RJ stands for registered jack (or many varients lost in time). A cable
is not a jack, a jack is the thing you plug the cable into. There's no
such thing as a RJ48X cable??? Anyway, the short is generally facing
the telco side. Ie. you suspect the customer has bogus gear, you have
them unplug it, now you have a hard loop back to you to test the
circuit all the way to that jack.

RJ48X jacks went out quite a while ago, mostly after the telcos stopped
being responsible for inside wiring at all (past their 90 day windows
or whenever they'll warantee their inside work now-a-days).

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?? Are you making your own patch cables? If you find it difficult, you
shouldn't be making your own patch cables. Buy them premade from the factory.
It sounds like alot of problems might go away then?  Thats what the
vast majority of the cable pros do, its not usually worth the time to
make them when they are like a buck a piece (not going to BestBuy to
spend $20 on something that costs less than a buck to make).

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Thats probably because you are looking for something that doesn't exist.
Nobody makes their own cables?


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None of my hundreds of instalations ever break using stock ethernet cabling.
I'd question what you are doing specificly to make it have a problem?


Re: E1and RJ48(C|X) cabling


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You're right, sorry for the abuse of terminology. If I understand you
correctly what I want is a
shielded cat5 cable with two RJ48c jacks crossover connected? Or a
RJ48C crossover cable for short.

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Ok. I thought this connector type might be helpful in diagnosing
connection problems on our end.

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Yes I am.

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That is the plan now ... hence question 3.

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We'll the cheapest I've found is @
http://www.stonewallcable.com/product.asp?dept%5Fid=134&pf%5Fid=SC%2D9598%2DHFX
where they sell a 3 ft. variety for $17.50. Only trouble is the
shipping to Europe.

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Not sure exactly what you mean.

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I think the answer to that question is: Making my own (bad) cabling.
I'm going to see if we continue having problems with the prefabricated
variety.

Thanks for your reply,

Mads


Re: E1and RJ48(C|X) cabling


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Okay, so you are hooking up two devices talking PRI locally? Rather
than a telco handoff which would handle the cross as basic wiring.

Finding premade crossover T1 cabling will be a bit harder to find cost
effective ones. They'll charge you heavily for doing something
different. :(

Here's somebody that wired up some easy to punch jacks in a crossover pattern.

http://www.voip-info.org/wiki/view/T1+Crossover+Cable

Some google searched only found the $20 premade T1 crossover cables premade.. :(

You don't need shielded cat5. If anything, you want the pairs shielded
against each other in a T1 cable, not shielded together into one bundle.
(ie. an ABAM cable).

As I mentioned, almost all my installations will get wired up to a box
or panel, and then patched over with bog-standard ethernet cabling.
You could extend the concept of the cross-over box mentioned above to
a set of two patch-panels if there are a lot of these runs, and not
have to worry about doing up the cables.


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Stonewall cable is not really all that cheap.

This is probably a straight through cable wired up to the pairs that
T1 uses. Did you need the straight throughs? Or the cross-over T1 cables?


Re: E1and RJ48(C|X) cabling


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For T-1/E-1 cabling try here also
http://www.blackbox.com/Catalog/Detail.aspx?cid=45,85,1402&mid=477

they have Authorized Distributors in these countries
http://www.blackbox.com/Contact_Us/distributors.aspx

Re: E1and RJ48(C|X) cabling


Doug McIntyre wrote:
(snip)

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I don't know if they are related, but RJ38X is similar, but the
shorts are (1,4) and (5,8).   They are commonly used for alarm
systems that connect to the phone line.  That allows the alarm
to have priority over the phone line when needed, but if unplugged
then house phones work normally.

-- glen


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