To introduce networking, lets start with wired networking as a foundation. Wired networking has some basic components that will help you when you deal with wireless networking.
We will lay the groundwork so that you can build upon your understanding of networking. I wont bore you with a dry, techie filled presentation of this topic. My intention is present networking in a basic straightforward and entertaining way. Ok, lets start building our groundwork.
If I met you on the street, there might be a handshake, eye contact, a simple nod of recognition. A simple three-step process to communicating, were establishing a connection.
What happens when computer A needs to communicate with computer B. Is there a handshake, eye contact, or a simple nod of recognition? Yes and no, obviously human behavior is not like computers. However, the two computers need to establish a connection for communicating. What behaviors would computers have to begin there talk?
Starting with a handshake, the two computers would have a cable connected between them. Eye contact would be the network interface cards or NICs in each computer. In addition, the nod of recognition would be baseband communications. How did I arrive at this analogy? Let me break this down into three parts.
First the handshake, a means of connecting. Remember we are discussing wired networking. A wire or cable is the means of connecting computer A and computer B. Because our analogy consists of just two connect computers, we will use a special type of cable called a cross-over cable.
The standard Ethernet cable contains eight wires. The colors of the wires are: orange/white, orange, green/white, blue, blue/white, green, brown/white, and brown. The pinouts, 1 through 8, would match from one networked device to another networked device. However, a network consisting of just two devices like our example, the pinouts are crossed. Note the different in our diagram below:
At each computer, the cable must be attached to something. What is the attachment?
Our second part is eye contact, the network interface cards [ NICs] our attachment. Eye contact is recognition of the handshake. Would you talk to someone who shakes your hand but wouldnt make eye contact? Eye contact is acknowledgement between the parties. There are three things to know about a NIC. Number 1, it attaches a computer to the network. Number 2, the NIC allows the computer to participate in sending and receiving data. Number 3, each NIC has a unique identifier called a Media Access Control address, or MAC address for short. The MAC address is the ID for each networked device. Back to our human analogy, we all have different forms of identification, maybe a divers license number or social security number. These are identifiers in our society.
Part three, the nod of recognition. A simple nod between us is the beginning of our communication or talk. I acknowledge you and you return the acknowledgement, now we start talking. So far, we have our two computers, their NICs, and one cable. Talking or sending data over the cable will be accomplished through Baseband communication.
What is baseband? Baseband is a signaling method describing how frequencies are transmitted. Baseband communication is used in many applications, such as; Transmission over twisted-pair cables, like Computer A and B
Local area networks (LANs) and metropolitan area networks (MANs) operating at 10-100 Mb/s using coaxial cable or optical fiber.
Broadband communications, on the other hand, is frequently used in a more technical sense to refer to data transmission where multiple pieces of data are sent simultaneously to increase the effective rate of transmission, regardless of actual data rate. In network engineering, broadband is used for methods where two or more signals share a medium.
The various forms of Digital Subscriber Line (DSL) services are broadband in the sense that digital information is sent over a high-bandwidth channel, whereas baseband is over a single pair of wires.
Back to our two computers. It looks like we are ready to communicate. We now have the two computers, with their NICs installed, a cross-over cable between then, and baseband to make communications possible. A handshake, eye contact, and the nod of recognition, were ready.
Loretta A. Steele, MCP, MCSE, over 25 years of computer experience in network design, installation, maintenance and training, technical support and programming. www.lincolnsteele.com
