LAN and Telecom Cabling Problem in Cable installation

Bookmark this page:  YahooMyWeb Yahoo!  Google Google  Windows Live Favorites Windows Live  del.icio.us del.icio.us  digg digg  Add to Netscape Netscape
Subject Author Date
Problem in Cable installation Siva U. Shankar 06-05-05
Posted by Al Dykes on June 5, 2005, 10:41 pm
Please log in for more thread options


>Siva U. Shankar wrote:
>
>> I've connected a 3com office connect 16 port switch like the following way
>> the netwotk is not working can u help me to figure out why?
>>
>> 3com office connect --> CAT5e 586A cable --> both end 586A wall socket
>> connected CAT5e cable --> straight through/ 586A cable --> to a winXP
>> computer
>
>Are you *absolutely* certain that *both* ends are 568A. If one end of
>the cable is terminated 568A and the other end is terminated 568B then
>you effectively wind up with a crossover cable and not a straight
>through cable.
>
>By the termination, I'm not talking about the cable, I'm talking about
>the jacks. There is no such thing as 568A or 568B cable. Cable is cable,
>It can be rated to be compatible with the 568 wiring specification, but
>the cable isn't 568A or 568B. What *is* important are the terminations
>(jacks) at each end. It's the way the cable is terminated that
>determines if it is 568A or 568B.
>
>You can buy jacks that are 568A and you can buy jacks that are 568B. As
>long as you pick one kind and just one kind and stick with it, all will
>be fine. Start mixing 568A and 568B and you'll start having these problems.
>
>> when connected this way it says in the computer, repeats these two
>> messages. - network cable is unplugged/acquiring network parameters (This
>> message is contineously repeated on its own. There is no connected lite
>> indicater in the switch either.
>
>And I'll bet that eventually you end up with a 169.154.x.x IP address,
>don't you?
>
>That's APIPA. Automatic Private IP Addressing. When a Microsoft box
>can't get an IP address from a DHCP server it turns to APIPA to randomly
>assign a class B address by default.
>
>> When i connect the computer direct to the 3COM office connect it works fine.
>
>So we've just eliminated the PC as a source of the trouble.
>
>I'm betting that you have a wiring problem between the jacks and patch
>panel.
>
>John

Back in the day before I had a budget for tools (and inhereted a
crappy infrastructure) I got a lot of use out of a 100 ft ethernet
patch cord. It was long enough for me to backhaul from the PC any
office to, in my case, the equipment closet patch panel, or even a
server.

One of these will let you do an end-to-end test, skipping
alll the existing parts.

If you get one take care of it. Get a plastic thingy used to coil up
power extension cords. Don't kink or step on it.



--
a d y k e s @ p a n i x . c o m

Don't blame me. I voted for Gore.


Posted by John P. Dearing on June 6, 2005, 2:50 am
Please log in for more thread options


Al Dykes wrote:

> Back in the day before I had a budget for tools (and inhereted a
> crappy infrastructure) I got a lot of use out of a 100 ft ethernet
> patch cord. It was long enough for me to backhaul from the PC any
> office to, in my case, the equipment closet patch panel, or even a
> server.
>
> One of these will let you do an end-to-end test, skipping
> alll the existing parts.
>
> If you get one take care of it. Get a plastic thingy used to coil up
> power extension cords. Don't kink or step on it.

Excellent idea!

I'd also make up a second one that is a crossover cable. Use a
completely different colored cable (like red or purple) so that you know
right away that this is the crossover cable.

John
--
John P. Dearing
A+, Network+, Server+
To reply: Just drop "YOURPANTS" in my address! 8-)


Posted by Siva U. Shankar on June 6, 2005, 3:02 am
Please log in for more thread options


Hi!

The computer side jack is a Leviton RJ45 jack. They have color coding for
both 568A and B on the same block. I've used the 568A

The actual cable is 568A CAT 6 UTP cable.

On the router side I used a LCT or ICT (I'm not sure 100%) terminal block
(four points in a block) the problem is there is no color marking on the pin
layout. But it gives a BIX block type connector from 1 to 8 from left to
right when u keep the clip side down. I've used the same pin color
combination as the other side.

U r right when i was trying different cable combinations on both jacks, at
one point I got the IP address as u suggested. I' was thrilled thinking it
is atlast started to work. But on the switch side no indication for a
connection!!!

Regards

Shankar


> Siva U. Shankar wrote:
>
> > I've connected a 3com office connect 16 port switch like the following
way
> > the netwotk is not working can u help me to figure out why?
> >
> > 3com office connect --> CAT5e 586A cable --> both end 586A wall socket
> > connected CAT5e cable --> straight through/ 586A cable --> to a winXP
> > computer
>
> Are you *absolutely* certain that *both* ends are 568A. If one end of
> the cable is terminated 568A and the other end is terminated 568B then
> you effectively wind up with a crossover cable and not a straight
> through cable.
>
> By the termination, I'm not talking about the cable, I'm talking about
> the jacks. There is no such thing as 568A or 568B cable. Cable is cable,
> It can be rated to be compatible with the 568 wiring specification, but
> the cable isn't 568A or 568B. What *is* important are the terminations
> (jacks) at each end. It's the way the cable is terminated that
> determines if it is 568A or 568B.
>
> You can buy jacks that are 568A and you can buy jacks that are 568B. As
> long as you pick one kind and just one kind and stick with it, all will
> be fine. Start mixing 568A and 568B and you'll start having these
problems.
>
> > when connected this way it says in the computer, repeats these two
> > messages. - network cable is unplugged/acquiring network parameters
(This
> > message is contineously repeated on its own. There is no connected lite
> > indicater in the switch either.
>
> And I'll bet that eventually you end up with a 169.154.x.x IP address,
> don't you?
>
> That's APIPA. Automatic Private IP Addressing. When a Microsoft box
> can't get an IP address from a DHCP server it turns to APIPA to randomly
> assign a class B address by default.
>
> > When i connect the computer direct to the 3COM office connect it works
fine.
>
> So we've just eliminated the PC as a source of the trouble.
>
> I'm betting that you have a wiring problem between the jacks and patch
> panel.
>
> John
> --
> John P. Dearing
> A+, Network+, Server+
> To reply: Just drop "YOURPANTS" in my address! 8-)




Posted by James Knott on June 6, 2005, 9:48 am
Please log in for more thread options


Siva U. Shankar wrote:

> The actual cable is 568A CAT 6 UTP cable.
>

There's no such thing as 568A cable. 568A or B only specifies how a cable
is connected. You'd use the exact same cable for either.


Posted by Justin Time on June 6, 2005, 12:48 pm
Please log in for more thread options


Guys,

Before you dig yourselves into a deeper hole regarding cable and if
they are 568A or 568B, you need to understand that cables marked as
568A or 568B meet the transmission requirements published in that
standard. You are confusing the standard with the wiring pattern.
Check out this link I selected at random where it talks about
applicable standards...

<http://bwccat.belden.com/ecat/jsp/Index.jsp?&P1=undefined&P2=undefined&P3=undefined&P4=undefined&P5=undefined&P6=undefined>

Rodgers Platt



Similar ThreadsPosted
Problem in Cable installation June 5, 2005, 2:15 am
Need telephone cable installation troubleshooting advice October 31, 2005, 4:42 am
problem between power and communication cable February 10, 2005, 4:18 pm
Ethernet STP Patch in STP installation July 25, 2006, 9:38 am
CATV design and installation links June 4, 2005, 3:12 am
Completely weird cable problem in new house - need insights pls! November 8, 2006, 9:50 am
Instruction for Leviton 1x9 Bridged Telephone Distribution Module installation January 18, 2007, 11:47 pm
SC Fibre problem?? September 10, 2004, 11:45 am
RS 232 protection problem May 5, 2006, 2:02 am
Fibre problem August 16, 2006, 6:43 pm
cat5 problem September 11, 2006, 8:45 pm
Advise on big fibre problem September 10, 2004, 4:37 am
Problem with Access Point wiring November 24, 2004, 8:36 am
Tektronix OF150 OTDR problem October 13, 2006, 10:15 am
Problem with fiber link locking network segment randomly July 9, 2004, 4:56 am