[comp.dcom.lans] another 10BaseT wiring question

lairdkb@mentor.cc.purdue.edu (Kyler Laird) (04/06/91)

I saw the front of a Gateway (?) concentrator and ordered network cabling
that terminates in modular (RJ-45) connectors.  I want this because I'll
have ~14 connections and only 12 ports on the concentrator.  (I don't intend
to ever use all at once.)

Unfortunately, we got a David System's concentrator which uses a 50-pin telco
connector.

I'm looking for something like a harmonica adapter that would allow me to
plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.

Any pointers?

Thanks!

--kyler

jbreeden@netcom.COM (John Breeden) (04/06/91)

In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
>I saw the front of a Gateway (?) concentrator and ordered network cabling
>that terminates in modular (RJ-45) connectors.  I want this because I'll
>have ~14 connections and only 12 ports on the concentrator.  (I don't intend
>to ever use all at once.)
>
>Unfortunately, we got a David System's concentrator which uses a 50-pin telco
>connector.
>
>I'm looking for something like a harmonica adapter that would allow me to
>plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.
>
>Any pointers?
>

Contact any of the large telco distributers (like Graybar), or AT&T Network
Systems - what you're looking for is pretty common - in the world of phones.

-- 
 John Robert Breeden, 
    jbreeden@netcom.com, apple!netcom!jbreeden, ATTMAIL:!jbreeden
 -------------------------------------------------------------------
 "The nice thing about standards is that you have so many to choose 
  from. If you don't like any of them, you just wait for next year's 
  model."

lairdkb@mentor.cc.purdue.edu (Kyler Laird) (04/07/91)

In article <1991Apr6.151024.7638@netcom.COM> jbreeden@netcom.COM (John Breeden) writes:
>In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
>>I'm looking for something like a harmonica adapter that would allow me to
>>plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.
>Contact any of the large telco distributers (like Graybar), or AT&T Network
>Systems - what you're looking for is pretty common - in the world of phones.

Hmm...I suspected this, but am wary.  The problem I assume I'll encounter is
a person who keeps saying "Sure, 6 RJ-45 (8 conductor) to a 50-pin telco.  No
problem."

I have already found a harmonica adapter with RJ-45's in and a 50-pin out.  The
problem I'm having is that RJ-45 is 8 conductor and 10BaseT is only 4 conductor
but it uses RJ-45 connectors (more on that in another ongoin thread...).  So
the adapters I've found so far (Inmac...) have only 6 (6*8=48) RJ-45's in.

So...I don't want what I assume would be a standard 'phone adapter since I
only want half of the connections (1,2,3,6 at that!) used.

I look forward to finding out that I'm wrong and life is good.  I'd appreciate
a pointer to Graybar.

Thanks!

--kyler

woody@ucscb.UCSC.EDU (Bill Woodcock) (04/07/91)

        > lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
        > I'm looking for something like a harmonica adapter
        > that would allow me to plug in 12 RJ-45 connectors
        > and come out with a 50-pin telco connector.
          
        > jbreeden@netcom.COM (John Breeden) writes: 
        > Contact any of the large telco distributers (like
        > Graybar), or AT&T Network Systems - what you're
        > looking for is pretty common in the world of phones.
         
        > lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
        > Hmm...I suspected this, but am wary.  The problem I
        > assume I'll encounter is a person who keeps saying
        > "Sure, 6 RJ-45 (8 conductor) to a 50-pin telco.  No
        > problem."  I have already found a harmonica adapter
        > with RJ-45's in and a 50-pin out.  The problem I'm
        > having is that RJ-45 is 8 conductor and 10BaseT is
        > only 4 conductor but it uses RJ-45 connectors (more
        > on that in another ongoin thread...).  So the
        > adapters I've found so far (Inmac...) have only 6
        > (6*8=48) RJ-45's in.
    
    At first glance I agreed with John Breeden.    I've  used  the  little
    8-pin harmonica  blocks many times, but I see your problem.  If memory
    serves, they're AT&T part number something-something 256,  and  always
    referred to  by their number.  They do indeed pass all eight pins, and
    wouldn't work for you to plug directly in.  Outfits like  Graybar  and
    Anixter  Brothers  might carry a part that does exactly what you want,
    but don't bet on it.   Phone  numbers  for  the  South  San  Francisco
    branches  are as follows, and they can give you numbers for your local
    branch:
    
        Anixter Bros.:  +1 415 352 3100
        GrayBar:        +1 415 871 7000
    
    What you might want to look into, though, is patch panels and  12-jack
    harmonica blocks  from  vendors  of  10BASE-T hubs.  I know for a fact
    that Farallon (+1 415 596 9100) makes at least one model of each,  and
    I  would  assume  that  their  competitors  (NeuvoTech, etc.) would be
    selling similar products.
                             
                            -Bill Woodcock
                             BMUG NetAdmin

_______________________________________________________________________________
     
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0010 : CC00 7C00 0C00 1000 2800 440  8200  40 
0020 : C000 4000 8000 C000 C 00  800  80  48 0 9           woody@ucscb.ucsc.edu
0030 : FF00 F000 7F80 CC00 CC 0 7 80 7 80 CC    6
0040 : CC00 7F80 9800 7800 CC00 CC0  CC 0 C 00                 2355.virginia.st
0050 : CC00 CC00 FC00 CC00 CC 0 2000 10 0 7 00 C 0
0060 : CC00 CC00 CCC0 4800 2 00 1 00 2 00 48 0 9            berkeley.california
0070 : 4800 2400 1200 1000 2800 4 00 8 00  E0 
0080 : 3000 6000 F000 6000  000 60 0 600  C0 0 01C                   94709.1315
     
_______________________________________________________________________________

andrew@jhereg.osa.com (Andrew C. Esh) (04/10/91)

In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
>I saw the front of a Gateway (?) concentrator and ordered network cabling
>that terminates in modular (RJ-45) connectors.  I want this because I'll
>have ~14 connections and only 12 ports on the concentrator.  (I don't intend
>to ever use all at once.)
>
>Unfortunately, we got a David System's concentrator which uses a 50-pin telco
>connector.
>
>I'm looking for something like a harmonica adapter that would allow me to
>plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.
>
>Any pointers?
>
>Thanks!
>
>--kyler

We have a David 10baseT in for eval, and it came with one. The thing isn't
really a harmonica, but is darn close. I'm pretty sure it came with the
David 10baseT cards that are in the box, but it's unmarked so I can't be
sure.

Before plugging anything in, be sure to check the pinouts of the David
50-pin socket on the front of the card, and check that the sockets in the
harmonica wind up being connected to the right pins. We found a harmonica
that worked fine for a terminal server, but the pins were wrong for
10baseT. All the pins for socket one were spread out as pin 1 on the first
four sockets, and so on for the rest. :-)
-- 
Andrew C. Esh			andrew@osa.com
Open Systems Architects, Inc.
Mpls, MN 55416-1528		Punch down, turn around, do a little crimpin'
(612) 525-0000			Punch down, turn around, plug it in and go ...

rick@lrark.UUCP (Rick Mobley) (04/10/91)

In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
 >I saw the front of a Gateway (?) concentrator and ordered network cabling
 >that terminates in modular (RJ-45) connectors.  I want this because I'll
 >have ~14 connections and only 12 ports on the concentrator.  (I don't intend
 >to ever use all at once.)
 >
 >Unfortunately, we got a David System's concentrator which uses a 50-pin telco
 >connector.
 >
 >I'm looking for something like a harmonica adapter that would allow me to
 >plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.
 >
 >Any pointers?
 >
 >Thanks!
 >
 >--kyler

I regularly install the HP Ethertwist hub. It has a 50-pin telco plug on the
rear of the unit which can be extended to something like an Ortronics patch
panel, for rack mounting, or you can purchase a 12-port harmonica available
from HP. I do not have the part number in front of me, but any HP distributor
can find it for you.

Hope that helps you somewhat.

-- 
rick@lrark.UUCP       *    bang path --> uunet!ddi1!lrark!rick    *
Ricky Mobley          *          LRTUG (501) 224-9454             *
1800 Sanford Dr. #4   *    GEnie Unix RT SysOp address LRARK      *
Little Rock, AR 72207 *     WB5FDP.AR.USA.NA wb5fdp.ampr.org      *

cmilono@netcom.COM (Carlo Milono) (04/10/91)

In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
>I saw the front of a Gateway (?) concentrator and ordered network cabling
>that terminates in modular (RJ-45) connectors.  I want this because I'll
>have ~14 connections and only 12 ports on the concentrator.  (I don't intend
>to ever use all at once.)
>
>Unfortunately, we got a David System's concentrator which uses a 50-pin telco
>connector.
>
>I'm looking for something like a harmonica adapter that would allow me to
>plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.

Well, the standard jack for 10BASE-T uses 8-wires...every 10BASE-T card
*I* have ever seen is keyed for 8-wires...so I would assume that you
want an adapter that is an amphenol (50-pin) on the Equipment side and
(ahem!) 96 wires on the (ahem!) jack side with 12x8 wires splayed in
the correct order - if that is what you want: NO, I haven't seen it.

However, there are makers of 12x4 (skipping the Violet/Slate pair),
at which point you would have four-conductor mounting/patch cords and
rather unstandard wiring at the station jack, at which point you would
have to re-wire when you use the jack for something else - IMHO, a poor
choice for wire management.

A suggestion:

Run the 50-pin Amphenol to 110-like hardware and cross-connect from there
to your station field.  Leave your four-pair alone from the closet to the
jack and sleep well into the future.
-- 
+--------------------------------------------------------------------------+
|  Carlo Milono:  cmilono@netcom.apple.com   or   apple!netcom!cmilono     |
|"When a true genius appears in the world, you may know him by this sign,  |
|that the dunces are all in confederacy against him."   - Jonathan Swift   |
+--------------------------------------------------------------------------+

german@uxh.cso.uiuc.edu (Gregory German) (04/11/91)

cmilono@netcom.COM (Carlo Milono) writes:

>In article <9736@mentor.cc.purdue.edu> lairdkb@mentor.cc.purdue.edu (Kyler Laird) writes:
>>I saw the front of a Gateway (?) concentrator and ordered network cabling
>>that terminates in modular (RJ-45) connectors.  I want this because I'll
>>have ~14 connections and only 12 ports on the concentrator.  (I don't intend
>>to ever use all at once.)
>>
>>Unfortunately, we got a David System's concentrator which uses a 50-pin telco
>>connector.
>>
>>I'm looking for something like a harmonica adapter that would allow me to
>>plug in 12 RJ-45 connectors and come out with a 50-pin telco connector.

>Well, the standard jack for 10BASE-T uses 8-wires...every 10BASE-T card
>*I* have ever seen is keyed for 8-wires...so I would assume that you
>want an adapter that is an amphenol (50-pin) on the Equipment side and
>(ahem!) 96 wires on the (ahem!) jack side with 12x8 wires splayed in
>the correct order - if that is what you want: NO, I haven't seen it.

>However, there are makers of 12x4 (skipping the Violet/Slate pair),
>at which point you would have four-conductor mounting/patch cords and
>rather unstandard wiring at the station jack, at which point you would
>have to re-wire when you use the jack for something else - IMHO, a poor
>choice for wire management.

>A suggestion:

>Run the 50-pin Amphenol to 110-like hardware and cross-connect from there
>to your station field.  Leave your four-pair alone from the closet to the
>jack and sleep well into the future.
>-- 
>+--------------------------------------------------------------------------+
>|  Carlo Milono:  cmilono@netcom.apple.com   or   apple!netcom!cmilono     |
>|"When a true genius appears in the world, you may know him by this sign,  |
>|that the dunces are all in confederacy against him."   - Jonathan Swift   |
>+--------------------------------------------------------------------------+

Well I have started to avoid any of the products with the 50pin connectors.
It is much easier to trouble shoot a problem or to switch a station from on
network to another when each port is connected with its own jumper to a
patch pannel rather than an Aphenol connector.

I think you will find that how you wire everything up will depend on how
you are setup to begin with.  We have 8 pairs going from the wire closet to
each station.  There is an RJ-45 on top for voice and a second (B-Jack)
for data.  In general we wire only 2 pair of a connection back to the
distribution location and terminate in an RJ-11 patch pannel.  Our jacks
are wired as inside pairs and outside pairs such that an RJ-11 plugged into
an RJ-45 jack at the end user's location will hit the inside pairs (5&6 here).

When we wish to use pairs 7&8 we use a custom splitter that provides 7&8 as
the middle pair on the B-side of the splitter and just passes 5&6 through
to the middle on the A-side.  We would wire 7&8 as a separate port on the
RJ-11 patch pannel.

When I am done with a building each station is wired to the patch pannel and
what we connect them to determines what kind of jumper we used.

For AppleTalk it would be a straight through cable from the patch pannel to a
StarController (or first to a 4:1 patch pannel like MacLAN then to the SC).

For 10baseT we use a cable that is 1234 on the RJ-11 end and 1236 on the RJ-45
end, one from the station to the 10baseT card or transceiver and one from the
patch pannel to hub.  

For Token Ring we also use straight through jumpers.

This system requires us to use custom jumper cables and drop cables for 10baseT
but allows us to use our distribution system in a more flexible fashion.  We
have had very little trouble getting cables made to our specs and make custom
length drop cables when we need to.

Sometimes it seems that the people who installed all this phone cable had no
idea that I would want to use it for data! :-)  It is hard to work out a system
that is both flexible and 100% efficient in use of cable.  AppleTalk really only
requires 1 pair, but in order to be able to switch to ethernet or 10baseT you
need to wire for 2 pair.  When I started out I knew that not every building
was going to be easy, but I had hoped that a few of them would be!


--
         Greg German (german@sonne.CSO.UIUC.EDU) (217-333-8293)
US Mail: Univ of Illinois, CSO, 1304 W Springfield Ave, Urbana, IL  61801
Office:  129 Digital Computer Lab., Network Design Office

andrew@jhereg.osa.com (Andrew C. Esh) (04/16/91)

I would rather avoid 50-pin stuff too. I have seen wiring closets where
they have gone wild with these things, and have introduced a lot of EMI
after all the cross connections. One place went from 8-pin ports to a
harmonica, 50-pin from the harmonica to an 8-pin port patch panel (incase
they wanted to re-assign ports) RJ45 (oops, I mean ISO 8877) straight
through jumpers to ANOTHER RJ45 panel, yet another 50-pin to 66 blocks, and
from there to the other IDFs to be punched through yet another panel. By
the time they got done there was so much EMI ingress the whole thing didn't
work. I think they got too prissy-neat-and-clean when they planned their
wiring. What's wrong with a mass of RJ45s going stright from hub to the
wall? I do it in my machine room. It works.

That leads me to my second pet peeve. If one wire becomes faulty in a 50-pin
jumper, the whole thing needs to be replaced. The other way, you just need
to replace the jumper for one port, and you can easily crimp that togeter
yourself. I keep a spool of wire, a crimper, and some 8-pin connectors in
the machine room just in case I feel the need. You never know when you
might need to patch something together. You need the spool anyway - if
someone's UTP in the wall is shot, you can temporarily run their port into
the next office and grab a spare off that guy's wallplate.

If you really need 50-pin, as is the case with the David 10baseT cards, try
calling David. I would be surprised if they don't supply the jumper as an
accessory to the card. I have a David in for eval at the moment, and a
50-pin jumper, along with a harmonica sort-of-thing came with it. Nowhere
does it say David on it, so it may be third party, but it works.

The thing to watch out for is the pinouts. I tried to use a Xyplex
10baseT harmonica and 50-pin for connection to a Terminal Server card in a
Xyplex Communications server. The ports wound up with the pins from port 1
(10BaseT) spread out as pin 1 on each of the first four serial ports, or
something akin to that. You'd think they would pin out their cards so the
same 50-pin jumper and harmonica combination would work for both of them.
Ho hum. Anyway, you should be able to get 12 ports (12*4=48) out of the 50
pin jumper, and be sure to check the pinouts so the ports, as distributed
on the 50 pin connector, each actually wind up in the right port in the
harmonica, in the right order, obviously.

"Let's go punchin' down,
 Everybody's learnin how,
 Come and cable networks with me"

 (apologies to the BeachBoys,
	"Fun, Fun, Fun, 'til her Daddy took the T-bird away")
-- 
Andrew C. Esh			andrew@osa.com
Open Systems Architects, Inc.
Mpls, MN 55416-1528		Punch down, turn around, do a little crimpin'
(612) 525-0000			Punch down, turn around, plug it in and go ...

jens@cadsun.corp.mot.com (Jens von der Heide) (04/17/91)

andrew@jhereg.osa.com (Andrew C. Esh) writes:

>I would rather avoid 50-pin stuff too. I have seen wiring closets where
>they have gone wild with these things, and have introduced a lot of EMI
>after all the cross connections.......
> ...... What's wrong with a mass of RJ45s going stright from hub to the
>wall? I do it in my machine room. It works.
>-- 
>Andrew C. Esh			andrew@osa.com
>Open Systems Architects, Inc.


	I'm a little bit dismayed that 50-pin connectors weren't included
in the 10BaseT standards.  Every set-up has its nuance, but, I've been
in closets were 400+ workstations were connected.  400 cross connects
are much nicer than a mass of RJ45 jumper cables.  I'd bet there are
more machines running with 50-pin connectors than the DB-9 connectors
included in the standard (Maybe I'm missing a large market, like 
defense related industries?).

	I'll agree its always desirable to limit the number of connections
in the chain.  We use one cross connect, from "station" to "data" in the
loop and it works quite well.
-- 
jens@corp.mot.com		Voice: (708) 576-3312
				 UUCP: uunet!motcid!jens