How to Set Up a Twisted Pair Local Area Network: Setting Up a Computer Network by Means of a Twisted Pair

Most computers are equipped with Ethernet 10/100Base-T network interface cards, enabling communication over the LAN cable. In case a PC has no such card, it should be bought and installed.

At the same time there exist various ways for setting up a computer network. If two PCs are to be linked, this may be done by means of Serial ports (so called Nullmodem), Parallel ports, or USB-to-USB cable. Though it will not be a full-function local area network, some network tasks can be solved.

Local area networks are divided by materials they are made of. The following variants may be used – a coaxial cable, a twisted pair, RadioEthernet (radio waves act as a signal carrier), fibre-optical cable. In order for a PC to work in such networks it should be equipped with corresponding network interface cards (NIC).

Networking Computers by Means of a Twisted Pair

If two PCs are to be linked, 2 RJ45 male connectors will be needed together with a twisted pair cable, RJ45 crimping tool, and assembly trays, in which the cable will be placed.

The twisted pair cable consists of 4 pairs of wires (Orange-White/Orange, Green-White/Green, Blue-White/Blue, Brown-White/Brown) in one jacket. Crimp the cable as shown below by means of RJ45 crimping tool.

Name — NIC1— Color — NIC2 — Name

TX+ (BI_DA+) — 1— White/Orange — 3 — RX+ (BI_DB+)

TX- (BI_DA-) — 2 — Orange — 6 — RX- (BI_DB-)

RX+ (BI_DB+) — 3 — White/Green — 1 — TX+ (BI_DA+)

– (BI_DC+) — 4 — Blue — 7 — – (BI_DD+)

– (BI_DC-) — 5 — White/Blue — 8 — – (BI_DD-)

RX- (BI_DB-) — 6 — Green — 2 — TX- (BI_DA-)

– (BI_DD+) — 7 — White/Brown — 4 — – (BI_DC+)

– (BI_DD-) — 8— Brown — 5 — – (BI_DC-)

This means that the white/orange wire should link the first pin of the first NIC with the third pin of the second NIC and so on.

This type of crimping is called Crossover and is used to connect the computers directly. The computers get linked by the given cable via the RJ45 female connectors on the NIC.

Network Setup

In order to adjust the PC settings (for Windows XP), go to Network Connections, then – Properties of Local Area Connection.

Internet Protocol (TCP/IP), File and Printer Sharing for Microsoft Networks, and Client for Microsoft Networks” should be installed here.

In Properties of TCP/IP protocol set the Subnet Mask similar for both computers (e.g. 255.255.255.0). The IP-address should be different in only last numeral (e.g. 192.168.45.1 for the first PC and 192.168.45.2 for the second).

In the Properties of My Computer, Change Computer Name in order for the Workgroup field to be similar for both PCs.

If more than two PCs should be linked, a Hub or Switch should be used. The cables to connect each PC to Switch/Hub should be crimped according to the following scheme (Straight):

NIC1 — Color Hub/Switch — Port

1 — White/Orange — 1

2 — Orange — 2

3 — White/Green — 3

4 — Blue — 4

5 — White/Blue — 5

6 — Green — 6

7 — White/Brown — 7

8 — Brown — 8

So, now everything should work well. And though nowadays many newer technical means are available for setting up a local area network, the twisted pair cable is still the cheapest and very convenient solution for both home and office. Most large modern networks still include twisted pair cables at some points.

As for the network interface card, it can be bouthgt at any computer store. Just tell a seller for what kind of a PC the card is being purchased.