Its truly amazing the number of technologies for connecting computers that exist today.
At Home Planet Networks we work with our customers to bring together the technologies that best fit the needs of our customers while providing the utmost in flexibility. Whether using standard UTP cabling, coax, fiber optic, wireless, powerline, or phoneline, we can customize a solution for you that will be easy on your wallet. If troubleshooting is required were not shy in bringing out the big test equipment guns to locate and correct the problem.
Ethernet back in the
early days came in two flavors 10 megabits and 10 megabits.
The difference depended on the cabling used.
10Base2 used coax
cable (similar to cable TV). 10BaseT
used the UTP (unshielded twisted pair) cabling which is used essentially
everywhere today. The coax
method was cheaper and the distance was a little longer.
The reason it was cheaper was because a hub was not required.
Each computer was connected in series: one after the other.
The downside showed itself on a regular basis.
Someone would unplug their computer from the network improperly
causing a break in the line between two nodes and all the other
computers on the line would suffer the consequences.
10BaseT requires that each computer has its very own cable running between it and a hub (or switch).
Because users could disconnect without disturbing anyone else or a cable could fail and only one computer would be impacted this robustness is why its the standard layout today.
If there is one thing computer users want, it's more speed. To satisfy this need, ethernet turned up the volume to 100 megabits per second. Early on this required fiber optic cable to be used in place of the much cheaper CAT5 copper cable most places already had installed. So 100 megabits languished until 100 megabits was made possible using the already existing CAT5 cabling. Users needed to replace the network interface cards in their pcs and they were off.
Gigabit Ethernet Hold on to your hats it gets faster yet. 1000 megabits per second is also available. It went through the same transition as the 100 megabit standard. First it was only supported on fiber, then on CAT5e. Notice the e this is enhanced CAT5 cable. For short runs standard CAT5 works flawlessly.
Now, we have talked a lot about wire and fiber optics and the speed supported by each. Where ever UTP is used a hub or switch is where all the wires meet. Whats the difference between a switch and a hub? Glad you asked. A hub or switch is an electronic device with multiple ports, like phone jacks. Each port can be connected via cabling to a computer or another hub or switch. Hubs direct traffic essentially by listening to all the computers connected to it and letting the loudest one talk. A switch on the other hand attempts to create virtual private channels between two nodes. Because there is no one yelling IS IT MY TURN YET? the data moves very quickly much faster than a same speed hub. Of course if all the nodes are trying to talk to the same destination you guessed back to yelling.
These traditional networking cabling schemes have been in use for years. They are reliable and reasonably inexpensive. However, wires are not convenient. Wireless was born. First running in the 900 MHz band, then moving to the 2.4 GHz band and now using the 5 GHz band. The higher the frequency used, the faster data can be transmitted. There are two different methods used by wireless networking radios to create reliable communication channels.
The first was FHSS Frequency Hopping Spread Spectrum. FHSS takes the entire band (in the US - 2.4 2.485 GHz) and slices it into 79 channels. Then each channel would be used for only a brief amount of time before hopping to the next channel. The 79 channels would be selected in a seemingly random pattern. Of course both radios need to know the hopping pattern if they are going to be able to communicate. Wireless networking cards that use this method in the 2.4Ghz band are referred to as the 802.11 standard. The speed of 802.11 networks can be up to 3 megabits per second. The main benefit is derived from the hopping using the entire allocated band. This allows the radios to essentially hop around any interference that may be present.
The second is DSSS Direct Sequence Spread Spectrum. DSSS does not hop about like the FHSS radios. Instead it spreads the radio energy over a range of frequency within the band. The 2.4 GHz band is divided into 11 channels however, only three can be used without causing overlapping (interference): the low end, the middle, and the high end. The benefit of this method is two fold higher throughput 11 megabits and greater range. Wireless networks that use this method in the 2.4Ghz band are referred to as the 802.11b standard or Wi-Fi. FHSS radios do a much better job getting through (or rather around) interference then do 802.11b radios. But speed won the battle.
Wi-Fi5 is DSSS running in the 5 GHz band. Throughput using these radios (802.11a) hums along a 54 megabits per second. There is even a turbo mode offered by some manufacturers boosting the speed to 72 megabits per second.
Unfortunately, the higher the frequency the harder time the radio energy has getting through things things like walls. So for close range and ultra high speed 802.11a is great, but if a larger area with many obstructions is being considered 802.11b might be a better choice.
One of the reasons 2.4 GHz is available as unlicensed radio spectrum has to do with the fact microwave ovens emit tons of radio emissions in this band. The microwaves emitted by the ovens are absorbed by the water molecules in the food being cooked. The water molecules become extremely hot with all this energy bombarding them and hence cook the food from the inside out. This also explains why 802.11b networks do poorly in heavy rain or going through trees. The water molecules in the trees or rain drops absorbs the radio energy leaving little to get to the other radio.
Wi-FiX the dark side. On top of water molecules stealing radio energy when 802.11x standards were written security was implemented by way of encryption. Meaning all the data transmitted between two radios is scrambled before being transmitted and then unscrambled after being received. This was called WEP (Wired Equivalent Privacy). It was discovered that WEP could be easily cracked using some software and a wireless network adapter. The attacker would listen to the wireless network collecting packets of scrambled data millions of them. Once enough packets had been collected the software would analyze the packets and determine the WEP security keys required to join the wireless network as a user. Once on the network all sorts of mischief could be had. Today WEP is still vulnerable. A future 802.11 standard will address security. There are options available to make breaking into a wireless network as difficult as possible these options are not activated by default and most end users are unaware of their existence.
As more computers are finding their way into the average household along with broadband internet access, manufacturers have developed some remarkable products to bring networking into places without dropped ceilings, raised floors, and wiring closets.
Two have already been discussed traditional ethernet cabling and wireless. There are two more networking technologies that make use of something every house already has phone jacks and power outlets.
Phone Line networking uses the existing telephone wiring installed in the building. The frequencies used are much higher then can be detected by telephone equipment or the human ear. Speeds up to 10 megabits per second are possible. A special phone line networking interface card is installed in each computer. A special router with phone line networking capability is connected to the broadband internet connection, thereby giving high speed internet access to every phone jack within the building. The down side to this method comes from two directions first, many older homes do not have phone outlets in every room. Second almost all new computers already come with a built-in ethernet card.
Power Line networking uses the existing power wiring installed within a building. A small device called a Power Line bridge plugs into the wall outlet. The bridge then connects to the computer using standard ethernet CAT5 cabling. Speeds up to 14 megabits per second are possible. An additional bridge will be required for each computer networking through the power lines. An additional bridge will be needed to connect the Power Line Network to a router for broadband internet access. Security is implemented using a passphrase. Only bridges with the same passphrase can talk to each other. The passphrase is used to scramble the data, but unlike WEP, it based on IPSEC which does not suffer from the same vulnerabilities. If the wiring within the building is inaccurate neutral and ground being switched for example the bridges may not be able to work in all rooms within a house. In large buildings where several separate power service feeds are used, the coverage will be even less.