EDGE

Fixed/Mobile	Mobile
Circuit/Packet	Packet/Circuit
Max Bandwidth	384Kb
Range	Coverage area of host network
Frequency	Frequency of host network
Host Network	GSM
Definer	ETSI (European Telecommunications Standards Institute)
URL	http://www.etsi.org/

EDGE (Enhanced Data rate for GSM Evolution) is a specification for data transfer on GSM networks.

EDGE features both a packet capability, EGPRS (Enhanced General Packet Radio Service), and a circuit switched capability, ESCD (Enhanced Circuit Switched Data).

EDGE packs up to 69.2Kbps into eight timeslots, for a total theoretical bandwidth of 473.6Kb.

GERAN (GSM/EDGE Radio Access Network) is the name given to the 3GPP standards for GSM/EDGE radio access.

EDGE is an update to GPRS. In turn, EDGE will eventually be replaced by WCDMA (Wideband Code Division Multiple Access).

EDGE Compact

The Universal Wireless Communications Corporation has introduced a standard for EDGE over IS-136 TDMA networks. This standard has been named EDGE Compact.

EDGE Compact supports 384Kbits over the more limited bandwidth provided by TDMA networks.

Additional Reading on EDGE

EDGE: Introduction of high-speed data in GSM/GPRS networks is an excellent technical overview of EDGE-EGPRS.

Ethernet

Ethernet is the most common LAN (Local Area Network) technology in use today.

Ethernet was developed by Xerox in the 1970s, and became popular after Digital Equipment Corporation and Intel joined Xerox in developing the Ethernet standard in 1980.

Ethernet was officially accepted as IEEE standard 802.3 in 1985.

The original Xerox Ethernet operated at 3Mbps. Ethernet networks up to 10Gbps now exist.

Ethernet Cabling

The first Ethernet standard, 10Base-5, ran over thick coaxial cable. A later standard, Ethernet 10Base-2, ran over a much thinner coaxial cable. These two versions of Ethernet were colloquially known as thicknet and thinnet.

Modern Ethernet standards run on UTP (Unshielded Twisted Pair) or fiber-optic cabling.

Ethernet Standard	Cable Specification
10Base-T	Category 3 UTP
100Base-TX	Category 5 UTP
1000Base-T	Cat 5e UTP
1000Base-SX	Optical Fiber

Ethernet Topologies

Ethernet 10Base-5 and 10Base-2 used a bus topology. Bus topologies were difficult to maintain and troubleshoot.

Modern Ethernet networks use a star topology with an Ethernet hub, switch, or router at the center of the star.

It is still possible to create a two-node Ethernet network in a bus topology using a null-Ethernet cable between the two devices.

Ethernet DTE and DCE

All nodes on an Ethernet network are either DTE (Data Terminal Equipment) or DCE (Data Communications Equipment).

Ethernet DTE are devices such as computers and printers which are trying to communicate on the Ethernet network.

Ethernet DCE are devices such as switches and routers which are trying to help other devices communicate on the Ethernet network.

Ethernet CSMA/CD

Like any network, Ethernet must have an algorithm for determining when each network node is allowed to communicate.

In Ethernet, this algorithm is known as CSMA/CD (Carrier Sense Multiple Access / Collision Detection).

CSMA/CD has proven to be a very capable, if highly anarchistic, algorithm.

How a Wireless Router Works

A wireless router is a wireless device that connects one computer or a whole network to another computer or network. It is possible to have a wireless network in your home or office. You will definitely come across wireless networks at most international airports. A wireless network is powered by a wireless router, which is responsible for sending information from one computer to another. The router will help you to share a single Internet connection between two or more computers, which can be on the same floor or even on different floors.

Working

A wireless router works in a similar manner as a wireless mobile phone. It is connected to a broadband cable or a Digital Subscriber Line (DSL) Internet connection and makes use of radio frequency wireless waves in place of telephone cables to broadcast and collect wireless signals. It allows data communication from one place to another. The information from the computer system is converted into a wireless radio signal before its communication. The wireless router interprets the radio signal after collecting it and subsequently transmits the data to the Internet through a wired connection. It can also accept data from the web, transform it into a radio signal, and then send it to a computer. A wireless network functions as a two-way radio communication system. It uses a similar method wherein radio and television programs are aired.

Models

It is necessary that you take a look at different models of wireless routers and check their specifications. Companies like D-Link have come out with some excellent high-performance wireless routers. Some other companies manufacturing wireless routers are Linksys, NETGEAR, and Belkin. Routers from these companies have excellent performance ratings.

Types

There are different types of wireless routers. The Linksys wireless-G broadband router and the Belkin router work in similar ways. These routers have a wireless access point that allows the consumer to connect to the G and B wireless connections. The routers also help connect wired Ethernet devices to the network. The devices on the network can share a high-speed Internet connection.

The Linksys wireless-B broadband router is another very popular router. It acts as a kind of a splitter for an existing Internet connection. So, as long as the Internet connection is attached to the router, all the computers that are located in your house or office will be able to use the Internet connection simultaneously. All the computers on the network will be able to connect to one another with the help of the wireless-B router.

Product Reviews

Before buying a wireless router, read the product reviews. Along with the wireless router, broadband VoIP technology is also available for long-distance communications. VoIP connections help to connect to the Internet as well as to use voice communications over the network. The wireless router antenna is a very important accessory for the wireless router. The antenna is used to intensify the radio signals emitted from other devices on the network. Hence, a long-range wireless router will definitely make use of the antenna.

Manufacturers

Companies like Micronet are venturing into manufacturing wireless networking products. Micronet has come out with its new SP916GK wireless router. This router is rated very highly for its excellent performance, and it features the latest technology in wireless routers for home and office users. Multiple users can share an Internet connection through a single ADSL connection. The router has an embedded DHCP server, a very simplified IP management system, as well as a firewall for security of the entire LAN.

How to Find your DNS Servers

The easiest way to find your DNS servers is by using the `nslookup` tool.

• Start nslookup
• Set your search type to NS -- this tells nslookup to search for nameservers
• Finally, enter in the domain name for which you would like to find the nameservers

Here are some example searches for the most popular lookups:

Finding the Lincsat DNS Servers

$ nslookup
> set type=ns
> lincsat.com
Server: 66.37.143.12
Address: 66.37.143.12#53

Non-authoritative answer:
lincsat.com nameserver = ns2.anywarenetworks.com.
lincsat.com nameserver = ns1.anywarenetworks.com.

Authoritative answers can be found from:

Finding the MCI DNS Servers

$ nslookup
> set type=ns
> mci.com
Server: 66.37.143.12
Address: 66.37.143.12#53

Non-authoritative answer:
mci.com nameserver = auth61.ns.uu.net.
mci.com nameserver = auth300.ns.uu.net.
mci.com nameserver = auth310.ns.uu.net.
mci.com nameserver = DNS1.mci.com.
mci.com nameserver = DNS2.mci.com.
mci.com nameserver = DNS3.mci.com.
mci.com nameserver = DNS4.mci.com.
mci.com nameserver = auth01.ns.uu.net.
mci.com nameserver = auth50.ns.uu.net.

Authoritative answers can be found from:
DNS3.mci.com internet address = 199.249.19.2
DNS4.mci.com internet address = 199.249.18.2

Finding the Shaw Cable DNS Servers

$ nslookup
> set type=ns
> shaw.ca
Server: 66.37.143.12
Address: 66.37.143.12#53

Non-authoritative answer:
shaw.ca nameserver = ns10sc.cg.shawcable.net.
shaw.ca nameserver = ns7.no.cg.shawcable.net.

Authoritative answers can be found from:
ns10sc.cg.shawcable.net internet address = 204.209.208.51

Finding the Comcast DNS Servers

$ nslookup
> set type=ns
> comcast.net
Server: 66.37.143.12
Address: 66.37.143.12#53

Non-authoritative answer:
comcast.net nameserver = dns02.jdc01.pa.comcast.net.
comcast.net nameserver = adns.cmc.comcast.net.
comcast.net nameserver = dns01.jdc01.pa.comcast.net.

Authoritative answers can be found from:
dns01.jdc01.pa.comcast.net internet address = 68.87.96.3
dns02.jdc01.pa.comcast.net internet address = 68.87.96.4

How to Change your IP Address

The IP address is a logical address assigned to your network card in order to establish communication over the network and also to identify your computer over it. IP addresses are usually assigned by network administrators based on certain rules and regulations.

Reasons to Change an IP Address

Even if you're part of a small network routed through a single IP address, the people outside your network can see only the IP address of the gateway you're using. If you're connected directly to the Internet cloud, it's basically the same thing. You're reaching out to a certain service through a certain IP address.

If someone would want to deny your access to certain services (an IRC channel, a certain forum, some websites, game servers and so on), they'd have to ban your IP address from the system. This puts you in a dilemma. The first thing that comes in mind is to change your IP address so you can evade the ban. Ban evasion is not recommended in any way as it may lead to a longer ban/denial of access. This doesn't have to be all negative. You can wish to change your IP address due constant flooding or spam you're being the victim of.

However, this tutorial will teach you a few tips and tricks on how to get things started in changing your IP address and how to actually change your IP address once the request has been approved.

If you're one of the old Dial-UP users with phone lines connected to your computer, you're most likely going to receive a different IP address if you're going to disconnect and reconnect the service. The same thing applies to those of you using PPPoE (Point to Point Over Ethernet) based on username/password since those are not permanent connections and they have to be reestablished every time you turn on your equipment.

The real problem comes for those of you using cable modems/DSL/FTTH connections. Most of you have static IP addresses, and if you don't, you probably have a bound IP address based on your Ethernet MAC address, so it still won't change.

The best thing to do in this case is to call your ISP and ask for suggestions on what to do next. Most likely, they have a special procedure regarding IP change requests. They will either provide detailed instructions on how to change your IP address either will give you the new settings available for immediate use.

In case of flooding and harassment, you might be asked for proof to sustain your statement. Get ready to show relevant logs extracted from your firewall and anything else you feel like it's going to be useful.

Once they have approved your request, you will only have to modify your settings, if your IP address is manually configured on the equipment. If so, you will have to change it to the new one your ISP gave you.

Steps to Change Your IP Address

Operating System	Steps to Change the IP Address
Windows 9x/Me users	Go to Start -> Control Panel -> Network -> Network card -> TCP/IP -> IP address
Windows XP/2k users	Go to Start -> Control Panel -> Network Connections -> Local Area Connection -> Properties -> Internet Protocol (TCP/IP).
Red Hat Linux	Go to System Tools -> Network. You could also use tools as 'linuxconf' or 'netcfg'tool.

Keep in mind that different ISP's have different procedures related to IP address changes and if you requested an IP change once and it was approved, it might not be approved so easily the next time

Computer Motherboard

We have already used the analogy that a CPU is the “brain” of your computer, so in comparison, a Computer Motherboard would be like the “central nervous system”. A Motherboard can also be called a Computer Mainboard. It is the most important circuit board in the computer system. The computer motherboard contains the bus (communication circuit for the computer components), the CPU, all memory sockets, expansion slots, etc.The bus speed is a key factor in determining the overall speed of a computer’s motherboard. Keeping all of this in mind, having a high-quality PC Motherboard is essential to having a high-quality computer.

Computer motherboards come in different configurations to fit different needs. A basic motherboard comes with several interfaces for all necessary components, and a BIOS (Basic Input/Output System) chip set to control the setup of the motherboard. Depending on what the computer is mainly going to be used for, it is important to keep BIOS manufacturers in mind when choosing a computer motherboard. Some manufacturers allow you to adjust the BIOS, while others do not. This option can allow you to overclock the system CPU.

When choosing a motherboard, there are a couple of other key factors to remember. Check the power supply to make sure it has the correct connectors for the motherboard you choose. Also make sure the CPU socket on the motherboard is compatible with the CPU you intend to install. Depending on the computer components you intend to run, make sure you have the correct video card slot(s), memory slots and other expansion slots. You also have to make sure the motherboard is capable of running the type and amount of hard drives you choose to run. You want a computer motherboard that supports more RAM than is currently needed to be prepared for new technological advancements.A good computer motherboard should be easy for you to set up (most motherboards today have color coded connectors and slots), support all of the components that you are running, and able to serve your future needs.

Computer RAM

Computer RAM is the best known form of memory your computer uses to temporarily store and access data. From the time you turn on your computer, your CPU is constantly using memory (RAM). Every time something is opened or loaded, it gets placed into RAM. This means it is put into a temporary storage area so the CPU can more easily access the information. From there it becomes a continuous cycle where the CPU requests data from RAM, processes it and then writes new data back to RAM. In most computers, this transfer of data between CPU and RAM happens millions of times every second. When an application is closed, the application itself, along with all its accompanying files is deleted from RAM. This is to make sure there is room for new data, so unless the changed files are saved to a permanent storage device, they will be lost.

Types of Computer RAM RAM Type: Pins: Usage: SDRAM 168 Typically only used in older and slower computers. RDRAM 184 Only used in certain Pentium 4’s with certain Intel chipsets. DDR 184 Faster version of SD RAM used in Pentium 4’s and Athlon DDR2 240 Newer version of DDR RAM with higher clock frequencies DDR3 240 Newer version of DDR2 with higher clock frequencies

Upgrading Computer RAM

When looking to upgrade your computer’s RAM, you will find RAM information typically displayed like this: 

1GB, 240-pin DIMM, DDR2 PC2-5300,

• 1GB refers to the size of the memory
• 240-pin refers to the number of pins used to connect to the motherboard
• DIMM- Dual In-line Memory Module
• SIMM- Single In-line Memory Module
• DDR2 refers to the type of memory
• PC2-5300 refers to the module type

Some other pieces of information you might find in a RAM description are:

• Clock frequency-refers to speed of the RAM in MHz (800MHz)
• CAS (Column Address Strobe) Latency-refers to the number of clock cycles that elapse from the   time the request for data is sent to the actual memory location until the data is transmitted from the  module. This is represented by a set of 4 numbers also known as RAM timing (4-4-4-12). These numbers stand for:
• TCL - CAS Latency Time
• Trcd - DRAM RAS# to CAS# Delay
• Trp - DRAM RAS# Precharge
• Tras - Precharge delay

Normally the BIOS will allow a user to adjust RAM timing to increase performance and stability.

Computer RAM

RAM is considered the most critical component in a computer system. Every bit of data must pass through RAM to get to the processor. Generic, low-cost RAM is most often the cause of data corruption and program crashes, so never skimp on the quality of RAM when upgrading. Make sure the RAM you choose is considered Grade A. Grade A RAM can only be found through major manufacturers, such as: Crucial.com.