Cisco Networking Academy * Del Mar College
ITNW 1325 - Fundamentals of Networking*
Instructor: Michael P. Harris
Semester 1 LABS
[Top] <#TOP> EIA/TIA-568-A Wiring Standard
T568A_Wiring.gif (10187 bytes) The EIA/TIA-568-A standard specifies two
wiring schemes to be employed in Category 3-5 UTP installations. The
difference between the T568A and T568B schemes is that pairs 2 and 3 are
reversed. Although 10BaseT only needs two pair (pins 1,2,3,& 6), all
four pairs must be terminated in either the T568A or T568B scheme. The
T568B scheme is the most popular. The color scheme should be consistent
throughout the system. The new 100Base-TX (IEEE 802.3u) uses the same
wiring scheme as 10BaseT (pairs 2 and 3) over Category 5 UTP.
[Top] <#TOP> Paired Wiring (T568) Faults
Paired Wiring Faults
[Top] <#TOP> Project #1 - Patch Panels & 110 punch-down cabling
patch panel Click Me! Category 5
patch panels are EIA 19? rack mountable and available in either 12, 24,
36, 48 or 96-port models. Front RJ45 jacks are connected to rear 110
terminals via a printed circuit board. The most popular wiring scheme is
T568B. The 110 terminals are color coded and the circuit board displays
the RJ45 pin out at each 110 punch point.
[Top] <#TOP> Network Cable Tester
Cable Tester Use a network cable tester (also known as a patch cable
tester) with the remote to test the continuity of individual cable
pairs. In /auto/ mode, the test sequences run automatically. Whereas the
/test/ pushbutton controls the sequencing of the test in the /manual/
mode. The universal testers will senses paired and non-paired wiring
faults <#PairedWiringFalts>. The master is used with the remote when
both cable ends are not accessible at the same location. It also can be
used as a bench tester for patch and jumper cables. Most models accept
both RJ45 and RJ11 plugs. Some models have an /on/off / switch to
prevent activating the tester when it is not in use. Some models also
include a pair of RJ45/BNC jack adapter cables; BNC plug-to-plug adapter
for testing coax cables; and RJ45 flat silver satin cable.
[Top] <#TOP> Project #2 - 10BaseT/100Base-TX patch-cable
Technically, as long as you build your 10Base-T/100Base-TX patch-cable
with straight-through connections for pairs 1 & 2 and 3, & 6 it will
work. But there are EIA/TIA 568 standards that specifies minimum
recommendations for telecommunications wiring within a structure,
including telecommunication outlets, and between structures in a campus
environment. It specifies a wiring system with a recommended topology
and distances. It specifies media by parameters which determine
performance and specifies connectors and their pin assignments to ensure
interconnectability.
EIA/TIA T568B EIA/TIA T568A
Using the USOC/PDS wiring pair color codes and the EIA/TIA T568B (AT&T
258A) wiring scheme assemble a /standard/ 10BaseT cable with
straight-through wiring using pins 1, 2, 3, & 6. Use a Network Cable
Tester <#Tester> (patch cable tester) to insure connection integrity.
usoc Universal Service Ordering Codes (USOC): are a series of
/Registered Jack/ (RJ) wiring configurations developed by the Bell
System for connection of customer premise equipment to the public network.
[Top] <#TOP> Banded & Solid / Wiring Pair Color Codes:
Pair # ID Pin #
T568B Band
code Pin #
USOC Solid
code
1 T1 5 White/Blue 5 Red
R1 4 Blue(White) 4 Green
2 T2 1 White/Orange 6 Black
R2 2 Orange(White) 3 Yellow
3 T3 3 White/Green 7 Orange
R3 6 Green(White) 2 Blue
4 T4 7 White/Brown 8 Slate
R4 8 Brown(White) 1 Brown
[Top] <#TOP> UTP Tech Notes:
*
*UTP Cable Stripping*
utp cable stripping The UTP cable's jacket is not exactly round
in shape. Since it is impossible to strip the jacket completely
without nicking the inner conductors, adjust the jacket cutting
blades so it only partially scores the jacket. Bending and
twisting the jacket at the score will complete the strip.
*
*UTP Cable Pulling*
Avoid stretching UTP cable. Pulling tension should not exceed 110N
(25 lbf) for 4-pair cable. Also the bend radius of 4-pair UTP
cable should not exceed 4 times the cable diameter. When cable
ties are used, install them loosely.
*
*UTP Cable Termination*
UTP cable pair twists must be maintained and untwisting must not
exceed 0.5 inches when installing Category 5 plugs and jacks and
when punching down into a 110 block. The cable jacket should only
be stripped back 0.5 inches for the plug and be held by the plug's
primary latching strain relief when crimped.
[Top] <#TOP> RJ45 Modular Plugs
The RJ45 modular plug was originally designed for silver satin cable
with stranded conductors and used for voice applications. Since all
conductors are side by side, this flat cable is easily stripped and
crimped into the plug. The conventional plug has in-line insulation
displacement contacts that pierce the middle of the insulation and
stranded wire when crimped as illustrated in Fig. 1. RJ45 plugs designed
for solid conductors have offsetting contacts that straddle and wedge
the cable?s solid conductor (Fig.2). If a RJ45 plug designed for
stranded conductors is crimped onto solid conductors, the blade?s
piercing teeth will be deflected and bent by the cable?s center
conductors resulting in an intermittent connection. However, the newer
tri-point plugs are designed for both stranded and solid conductors and
will successfully terminate both types of conductors. NOTE: AMP« RJ45
plugs shown in Fig. 3 have a differently spaced secondary strain relief
cavity. The industry standard crimp die with both primary (A) and
secondary (B) cable strain relief indenters will cause damage to the
AMP« RJ45 brand plug or tool because of this non-alignment. for stranded
utp for solid utp
RJ45 modular plugs
RJ45 Plugs
CAT5 RJ45 modular plug contacts have 50 micro? of gold plating,
compliant with FCC Part 68, Subpart F requirements. The RJ45 plug has an
oval cable opening suitable for both round and flat cable. Although the
RJ45 plug is primarily designed for solid conductors, it will
successfully terminate both solid and stranded conductors. Most RJ45
plugs are compatible with most industry standard crimp tools except AMP
tools.
[Top] <#TOP> Project #3 - 10BaseT/100Base-TX Cross-cable
To direct-connect two 10BaseT NIC's for testing or trouble shooting you
will assemble a 10BaseT/100Base-TX cross-cable (sometimes called a UTP
null-modem cable or plug-to-jack cable). This cable will allow you to
connect two 10BaseT or 100Base-TX nodes together without the need for a
concentrator. This can create a two-node LAN. Be sure to check the
wiring with the /Patch Check/ test tool.
Ethernet cross-cable
Category 5 Cross-Over Cables
cross over chart Category 5 cross-over cables are used to connect
hub-to-hub, adapter card -to-adapter card
and T568A-to-T568B applications. For example, cross-over cables must be
used in uplinking hubs and peer-to-peer
applications such as interconnecting two PC?s with Windows 95.
Cross-over cables tie the transmit pair (pins 1 & 2) to receive pair
(pins 3 & 6).
NOTE: Look carefully at the basic 10BaseT / cross cable/ diagram. Now,
imagine a cable fabricated as EIA/TIA 568B on one side
{W/O,O,W/G,B,W/B,G,W/N,N}
EIA/TIA T568B (RJ45 pinout) 1 2 3 4 5 6 7 8
TD+ TD- RD+ N/C N/C RD- N/C N/C
... and T568A {W/G,G,W/O,B,W/B,O,W/N,N} on the other side
EIA/TIA T568A (RJ45 pinout) 1 2 3 4 5 6 7 8
TD+ TD- RD+ N/C N/C RD- N/C N/C
... what would you have? ... an *Ethernet cross-cable*!
[Top] <#TOP> Project #4 - Surface-mount 110 Box
110 surface mount box Category 5 surface mount jacks can be Keystone or
printed circuit type that meet 100 MHz requirements. The 110 type
connecting blocks are connected to the RJ45 in accordance with the
T568A/B standard. RJ45 jack contacts have 50 micro? of gold plating. A
tie wrap attached to the circuit board provides cable strain relief.
Wall plates can have a double-sided adhesive pad for mounting; they may
also be screw-mounted. Surface mount boxes may come in single or duplex
models.
[Top] <#TOP> Project #5a - Roll-Over cable
Modular Plug & Jack Wiring Schemes:
USOC modular wiring Typically, modular patch cords are used for two
basic applications: data and voice (phone, modem and fax). Normally data
network patch cords are wired ?straight-through? (pin 1 to pin 1, pin 2
to pin 2, etc.). Voice patch cords are wired ?crossed? (pin 1 to pin
6/8, pin 2 to pin 5/7, etc.). The USOC scheme is used for voice and not
data because poor transmission performance is experienced with this type
of cable and scheme.
To connect to a Cisco router's console and/or auxiliary port you will
need a RJ45-to-RJ45 /roll-over/ cable (5a) and RJ45-to-DB9F DTE Terminal
adapter (5b). You can identify a /roll-over/ cable by comparing the two
RJ45 modular ends of the cable. Holding the RJ45 plugs side-by-side with
the tab at the back, the wire connected to the pin on the outside of the
left plug should be the same color as the wire connected to the pin on
the outside of the right plug (ie. mirror image or 180 degrees different
from each other). A /roll-over/ cable reverses pair 1 (pins 4 & 5), pair
2 (pins 3 & 6), pair 3 (pins 2 & 7), and pair 4 (pins 1 & 8).
Using the thin, flat, modular cable and two RJ45 plugs fabricate a
roll-over cable by crimping the RJ45 to one end using the standard USOC
color codes. Then before crimping the other side "roll over" (flip 180
degrees) the RJ45 plug.
Cisco Console Port Signaling and Cabling Console Port Roll-Over Cable
Terminal Adapter Console Device
DTE Signal RJ45 plug USOC Color RJ45 plug RJ45 jack T568 Color DB9F pin
DTE Signal
RTS 1 brown 8 8 slate 8 CTS
DTR 2 blue 7 7 brown 6 DSR
TxD 3 yellow 6 6 yellow 2 RxD
GND 4 green 5 5 green 5 Signal Ground
GND 5 red 4 4 red
RxD 6 black 3 3 black 3 TxD
DSR 7 orange 2 2 orange 4 DTR
CTS 8 slate 1 1 blue 7 RTS
NOTE: On some modular cables/adapters, the slate conductor is white .
[Top] <#TOP> Project #5b - RJ45/DB9F Terminal Adapter
(Cisco console cable)
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[TOP of Page] <#TOP> This page is maintained by: Michael P. Harris
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Last modified Jun 30 [E-mail]
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Copyright ¨ 1999