The Benefits of Networks
On a base level, any time two electronic devices are connected to each other so they can communicate, you have a network. Many people in the modern world have built simple networks without even realizing it - the act of connecting an MP3 player to a computer so one can transfer music files over is a basic and user-friendly form of networking. The advantages of networking are apparent in that same example; being able to share data across the network allows you to achieve a result easily with the two
devices combined that would, at the minimum, be substantially more difficult than if they weren't connected. The computer can connect to the internet to download music quickly and store a huge amount of it on its internal hard drives (especially in today's world of the $80 1TB HDD). The MP3 player, if it can access the internet at all, is probably slower and almost certainly has less storage space than the PC, but it's small enough to take with on a jog or in the car with a minimum of hassle.Other benefits of networking (beyond portable music) include the diminished need for devices in a business setting. If everybody can use one printer, one internet connection, and one centralized server or NAS, it cuts down dramatically on the cost in time, space, and money of setting up a digital office and allows for easier collaboration, too. Need to send the spreadsheet file down to Tom in accounting? No problem. Just send it to his computer via the network rather than putting it on a disk and walking it down to him like they did in the old days.
Networking also makes wondrous things like SaaS available, a good example being Google Docs. Which allows a group of collaborators spread all over the world to use the same program to edit the same files without ever meeting face-to-face.
The Flavors of Networking
Networks come in a variety of flavors, but the most common types are peer-to-peer and client/server.
Peer to Peer networking: Peer-to-peer (abbreviated P2P) networks are links of direct communication between two or more computers. No computer exercises any sort of authority over the other(s) and no computer screens any traffic as it passes between two computers on the network. Peer-to-peer has something of a shady reputation from the old days of Napster,
Kazaa, and the like, and it continues today as bazillions of people use P2P BitTorrent connections to pirate movies, music, and computer software at a rate that would bring a tear to Edward Teach's eye. However, P2P utility doesn't stop there - if you've ever used Skype to talk to someone over the internet, you've used a P2P network. Walkie-talkies are a simple P2P network. P2P networks are simple to configure and cheap, but they suffer from inflexibility, potential insecurity, impracticality once they get large, and of course, their shady reputation. Yarr.
Client/Server networks also have the advantage of being potentially much more secure. Servers can impose access limits, various forms of authentication, and other controls on traffic moving throughout the network. This type of network also makes things like printer sharing a workable reality. Their biggest downside is that they can get complex pretty quickly.
LAN, MAN, and WAN are terms used primarily to describe the size and scope of a network.
LAN: A LAN, or Local Area Network, is a network typically confined to a single building. That doesn't, however, mean that it's small. The single server and 18 workstations (13 cash registers, 4 search terminals, and 1 receiving computer, plus 7 handheld mini-computers used for inventory) that I have at my current workplace is a lot smaller than the network used at the MCC (the college I attend) but both are LANs because they're both confined to a single building. (MCC says that it's multiple buildings for organizational purposes, but you can walk through them all without ever stepping outside, so screw it, it's a LAN.)
MAN: A network that extends beyond the boundaries of a building (again, no matter how huge - even the Pentagon is still just one building!) becomes a MAN, and no that doesn't mean it's undergone some rite of passage or that it's somehow a male network now - MAN stands for
Metropolitan Area Network. An example of a MAN is a modern military base (particularly an Air Force one) with a large number of computers spread around various building all part of the same network.
WAN: The 800lb gorilla of networks, WAN stands for Wide Area Network. Wans cover even bigger areas than MANs. If you have a computer in Miami communicating with a computer in Anchorage (or even one in Atlanta) congratulations, you have a WAN. The internet can be seen as a humongous WAN.
Peer to Peer networking: Peer-to-peer (abbreviated P2P) networks are links of direct communication between two or more computers. No computer exercises any sort of authority over the other(s) and no computer screens any traffic as it passes between two computers on the network. Peer-to-peer has something of a shady reputation from the old days of Napster,
Kazaa, and the like, and it continues today as bazillions of people use P2P BitTorrent connections to pirate movies, music, and computer software at a rate that would bring a tear to Edward Teach's eye. However, P2P utility doesn't stop there - if you've ever used Skype to talk to someone over the internet, you've used a P2P network. Walkie-talkies are a simple P2P network. P2P networks are simple to configure and cheap, but they suffer from inflexibility, potential insecurity, impracticality once they get large, and of course, their shady reputation. Yarr.Client/Server Networks: This is where the real fun starts. Client/Server networks rely on a central computer (called a sever) to route traffic around the network to other computers called (three guesses...) Clients. Clients are usually personal computer. In an office environment, they're typically called workstations. Another way to think of how traffic moves around a client/server network is the post office or a shipping company.
Instead of directly moving the mail from its origination point to its endpoint, it goes to a hub of some sort first and is then sorted and sent on its way from there. This is inefficient if you, say, want to send something to your neighbor (that's a better use for a P2P type connection) but what if you want to send a bunch of packages (like Christmas cards, for example) to a bunch of people? Suddenly the P2P model is a lot less efficient.
Instead of directly moving the mail from its origination point to its endpoint, it goes to a hub of some sort first and is then sorted and sent on its way from there. This is inefficient if you, say, want to send something to your neighbor (that's a better use for a P2P type connection) but what if you want to send a bunch of packages (like Christmas cards, for example) to a bunch of people? Suddenly the P2P model is a lot less efficient.Servers: Typically servers are fairly powerful (and often expensive) computers. Modern servers often have several fast multi-core processors, a large amount of storage, etc. Prices for them in the tens of thousands of dollars are not uncommon at all.
Clients: Client computers are typically "normal" computers. They typically only cost tens of thousands of dollars when their owner is a rabid gamer.
Client/Server networks also have the advantage of being potentially much more secure. Servers can impose access limits, various forms of authentication, and other controls on traffic moving throughout the network. This type of network also makes things like printer sharing a workable reality. Their biggest downside is that they can get complex pretty quickly.
LAN, MAN, and WAN are terms used primarily to describe the size and scope of a network.
LAN: A LAN, or Local Area Network, is a network typically confined to a single building. That doesn't, however, mean that it's small. The single server and 18 workstations (13 cash registers, 4 search terminals, and 1 receiving computer, plus 7 handheld mini-computers used for inventory) that I have at my current workplace is a lot smaller than the network used at the MCC (the college I attend) but both are LANs because they're both confined to a single building. (MCC says that it's multiple buildings for organizational purposes, but you can walk through them all without ever stepping outside, so screw it, it's a LAN.)
MAN: A network that extends beyond the boundaries of a building (again, no matter how huge - even the Pentagon is still just one building!) becomes a MAN, and no that doesn't mean it's undergone some rite of passage or that it's somehow a male network now - MAN stands for
Metropolitan Area Network. An example of a MAN is a modern military base (particularly an Air Force one) with a large number of computers spread around various building all part of the same network.WAN: The 800lb gorilla of networks, WAN stands for Wide Area Network. Wans cover even bigger areas than MANs. If you have a computer in Miami communicating with a computer in Anchorage (or even one in Atlanta) congratulations, you have a WAN. The internet can be seen as a humongous WAN.
Other "ANs"CAN: Campus Area Network
GAN: Global Area Network
PAN: Personal Area Network (in this case not actually a network at all - just a wire management system, but can also refer to things like a bluetooth headset and cell phone)
"Okay, So How Do You Build One?"
Networks do not just spring up out of the proverbial earth. Like any other complex device, they need to be assembled. Here's a list of some of the more common components you'll see when building a network:
Hardware and Software
- Client: A computer (or sometimes the person behind it) that asks for data, access, or other resources from a...
- Server: A computer at the center of the network that manages the resources the client asks for.
- NIC: Network Interface Card. This is where you plug the cables that connect computers to each other on a wired network in. Most modern PCs come with at least one standard on the motherboard.
- NOS: Network Operating System. A server OS optimized for, well, server tasks. It's great at routing data around the network, but probably wouldn't be your first choice for, say, computer games.
- Node: Something on the network with a unique address. The Server is a node. So is each workstation. So, for that matter, is that crummy old printer that's destined for a beatdown in the parking lot someday.
- Connecitivity Device: A device used to connect multiple networks or multiple parts of a network to each other. The DSL modem/router your home ISP gave you would fall into this category. Companies like Linksys and D-Link make a lot of their money selling consumer Connectivity Devices.
- Transmission Media: The wires or radio waves used to actually transmit packets around a network.
General Concepts:
"So What do I do With it?"
So we've established how networks go together and their component pieces, and even what the benefits of them are, but not the Why to go with the What and How. Here are some common uses of networks:
- Segment: If the network is a city, a Segment is a neighborhood wrapped around a cul-de-sac. It's a bunch of devices (nodes) that use the same communication channel for their traffic.
- Backbone: The part of the network that does all the traffic management. Usually made up of Servers and Connectivity devices.
- Topology: The actual, physical shape the network takes (or at least the one it takes if you draw a diagram). A P2P network would look like a so-called "ring" or "bus" layout, with a bunch of computers all connected in a line (bus) or, well, ring. A Client/Server network will have more of a "star" configuration, with connections radiating out from a central point.
- Protocol: A standard method or format that is used for communication between the nodes on a network. Protocols are important, because without them, you'd never get reliable data transfer. Data is broken into packets before being sent, and if these get jumbled, you might as well have pseudo-random "noise" at the end for all the good it'll do you.
- Packets: Basically bite-sized chunks of larger blobs of data. Big files are chopped into packets before transmission.
To picture how data transfer with packets over a network goes, just imagine getting a bicycle shipped to you via UPS or a similar carrier. Instead of putting the bike pre-assembled in a HUGE box and sending that, the manufacturer will probably break it down into three: you'll get a round box with the wheels, the frame with a label on it, and a box with all the smaller parts (tires, chain, gear shifter, etc.) in it. When the packages arrive, they'll say something like 1 of 3, 2 of 3, and 3 of 3 and you'll have to assemble them from there. Packets work kind of like that.
- Addressing: Remember those unique addresses all the nodes have? This is the system used to assign them. A common and widely-used type of address that a node might have is an IP (Internet Protocol) address. Those are what's used on the Internet to route traffic.
So we've established how networks go together and their component pieces, and even what the benefits of them are, but not the Why to go with the What and How. Here are some common uses of networks:
- Communication: I mentioned Skype back under P2P networks, but there's also Vonage, Ventrillo, and other VOIP (Voice Over Internet Protocol) services out there, to say nothing of Instant Messenger clients, email, forums, newsgroups, Blogs, and (God help us) even Twitter. Oh, and that cell phone you've got? It's part of a network, too.
- File Sharing: You're on the first floor. Your boss, on the eleventy-third floor needs that document now. The elevator is running slow as usual. And you don't want to run up eleventy-two flights of stairs. Send it to him through the network. Not only have you saved yourself the time of actually walking there, you don't have to take the time to write the file to a disk, CD, or USB drive, either.
- Printer Sharing: So there's thirty of you in the office. You tell me what's a better use of the money - a cheap, crummy printer on every desk that gets in the way anyhow or a halfway decent one that you all share and better coffee in the office? Especially since none of you print much anyhow. Similar principles apply to sharing of other resources, too. (For example, scientific instruments)
- Cloud Computing: This is getting more popular these days. I already mentioned Google Apps, but things like Amazon's S3 would also apply, here.
- Gaming: Ever been to a LAN party? They're fun. A bunch of people supply their own computers, create a temporary LAN, and play some sort of multi-player game. Good clean fun.
- Secure Access: If you've got important data that needs to be seen by only certain eyes, a properly bolted-down network can make being sure that those eyes and ONLY those eyes see it much, much easier than doing the old routine where you handcuff a case to some guy's arm.
- Management Services: Or, keeping the IT department from going hair-pulling bald. Networks offer a lot of flexibility and functionality for managing the individual nodes hooked up to them. It's possible to do things like tracking software usage, software-level system maintenance, etc. from a server on a network rather than walking around and sing each workstation separately. One can also monitor and regulate user behavior from a central location.
[This post written in Mozilla Firefox 3.5 under Windows XP]
