Tiplord Windows 95 &Windows 98 Tips

Bookmark me Annoyances Boot Disks Customizing Device Manager
FAQ Hardware Networking Setup Switches Shortcuts
Software Help Updates Tip Ring Home

Twisted Pair Ethernet (10baseT/UTP)

Note: most of the rules for 10BaseT are also valid for Twisted Pair Ethernet (100baseTX/100BaseT4)

Twisted Pair Ethernet (10baseT), sometime also called "UTP" from "
Unshielded Twisted Pair", is based on using a cable similar to phone-wiring. The cable is connected via an RJ-45 connectors to the network card installed in the PC.

If you have a Combo / Multi-Connector network Board, check whether you need to configure the RJ45 plug (it is not alwas done automatically ! ).

These Twisted Pair cables connect now each PC to the "

which is amplifying and distributing the signal to other connected systems.

Hubs are available in different configuration, with 4, 8, 12, 15 or 24 RJ-45 connections (and most models offer also a BNC-connector for connection of a 10base2 Thin Ethernet cable).

When the network grows, you may need a second hub:

Warning: there are different cable to connect the hubs ! If the hub has only regular connectors, the cable MUST be a cross-cable ! However, some hubs offer special connectors for use of 'Standard' cables to connect between hubs (that depends on the hub, check the hub's manual)or a switch, able to select : 'workstation' or ' hub' connection.

For even larger networks, more hubs are required:

Again, watch out for the type of cable required to connect the hubs.

Often , you find a combination of Twisted-Pair and
Thin Ethernet (10base2) cabling:

A Thin-Ethernet cable is used to connect the hubs, such a cable is then often called "the
backbone", because it carries all the traffic to/from the server.
Warning: the
Thin Ethernet (10base2) backbone MUST follow the 10base2 specifications (length, terminators,...).
Warning: a network cannot grow unlimited in the number of hubs and repeaters
(see: Large Networks: 5-4-3 Rule) and on very large network configurations, it may be required to install Switches to optimize the network utilisation.

When connecting just 2 PC's together, there is a possibility to do it without a hub:

BUT: it is now a different type of cable: a crossed 10baseT cable.
Using a 'regular' cable (which is supposed to be used for connection to a hub) is a common cause of error, such a 'regular' or 'straight' 10baseT cable does NOT work in such a configuration without a hub.
I strongly suggest to purchase a cable, but if you think you can make it properly, here is the layout of such a crossed 10baseT-cable (i.e 10 MHz, this cable is NOT for 100baseT/100Mhz, for that look at
i.e 10 MHz, this cable is NOT for 100baseT/100Mhz, for that look at i.e 10 MHz, this cable is NOT for 100baseT/100Mhz, for that look at Twisted Pair Ethernet (100baseTX/100BaseT4) )

pin pin
1 <--------------------------------> 3
2 <--------------------------------> 6
3 <--------------------------------> 1
4 < not used >
5 < not used >
6 <-------------------------------------> 2
7 < not used >
8 < not used >

On Category 3 or 5 grade Twisted pair cable, it should be wired as:

Pin wire signal
1 White/Orange Transmit -
2 Orange/White Transmit +
3 White/Green Receive -
4 Blue/White  
5 White/Blue  
6 Green/White Receive +
7 White/Brown  
8 Brown/White  

where pin1 is the one on the left if you hold the RJ45 connector with
the pins facing up. 4,5,7,8 not used in 10mb network.

To make a Cross Over patch cable for hub to hub or computer to computer connections:

Pin Connector#1 <---cable---> Pin Connector#2
1 White/Orange   1 White/Green
2 Orange/White   2 Green/White
3 White/Green   3 White/Orange
6 Green/White   6 Orange/White

for distances over 10ft, the "pairs" are important for data loss prevention.
[less errors due to electromagnetic fields].

Where is Pin#1: