The speed of a wireless network depends on several factors particularly the protocols being used. The signal range a WiFi wireless network supports also affects its overall speed. These frequently asked questions cover the essential concepts in wireless network performance.
How Fast is Wireless Networking?
The speed of a wireless network depends on several factors including the Wi-Fi technology standards it supports.
How Fast Is 802.11g WiFi?
The 802.11g standard for wireless networking supports a maximum bandwidth of 54 Mbps. Yet some 802.11g-compatible home networking products may advertise speeds of 108 Mbps or more. How fast, then, is 802.11g Wi-Fi networking?
zSB(3,3)
What is the Actual Speed of an 802.11b Wi-Fi Network?
The theoretical bandwidth of an 802.11b Wi-Fi wireless connection is 11 Mbps. However, this level of performance is never realized in practice due to network overhead and other factors.
How Strong Is Your WiFi Wireless Signal?
The performance of a WiFi wireless network connection depends in part on the strength of radio signals between the devices. Several different methods are available for calculating wireless signal strength.
How Fast is a Cell Phone Modem?
Most cell phones can be used as a computer modem for portable Internet access. Cell phone modem speeds vary greatly but are generally much slower than residential Internet services.
Why Does My WiFi Data Rate Keep Changing?
Wi-Fi network connections automatically adjust their data rate (connection speed) based on the quality of the communication signal. Sometimes called "dynamic rate scaling," this feature of Wi-Fi extends the range at which wireless devices can connect to each other.
What is the Signal Range of a Wi-Fi LAN?
The range of a typical home Wi-Fi LAN varies substantially depending on a few key factors.
How Can the Range of a WiFi Network Be Extended?
Boost the coverage of your wireless LAN by strategically adding more equipment. Alternatively, a few simple tweaks to your router (access point) may also do the trick.
Can The Signal Range of a Wi-Fi Laptop be Increased?
When using a laptop with public hotspots, a strong wireless signal is necessary. Laptops with limited range are likely to suffer from slow or dropped Internet connections. Here are some ideas for improving the signal strength and range of a laptop to ensure best possible connectivity.
Which Wireless Router Has the Best WiFi Signal?
Consumer wireless routers vary in the WiFi range they support. Routers with stronger WiFi signals allow devices to connect at higher speeds from a greater distance and stay connected more reliably. Which wireless router then, has the best WiFi range?
Tuesday, December 29, 2009
Network Speed Tweaks - Connection Speed
Tweak the performance of your Internet or other network connection using these easy tips and tricks to optimize network speed.
DSL and Cable Broadband Speed Tweaks
Broadband tweaks are optimizations you can make to your computer and local network to increase the performance of your broadband Internet connection.
Do Internet Speed Optimization Tweaks Work?
Speed tweaks promise to optimize your Internet connection so you can, for example, play online games with less lag. Do they work?
zSB(3,3)
Download Accelerator Plus - Find Free and DAP Premium Downloads
Download Accelerator Plus is available as both a free package and a paid Premium version. Download managers like Accelerator Plus and Premium better utilize the bandwidth of home network connections.
TCP Optimizer
This Windows utility automatically tunes your computer's TCP/IP network settings for improved performance.
DSL and Cable Broadband Speed Tweaks
Broadband tweaks are optimizations you can make to your computer and local network to increase the performance of your broadband Internet connection.
Do Internet Speed Optimization Tweaks Work?
Speed tweaks promise to optimize your Internet connection so you can, for example, play online games with less lag. Do they work?
zSB(3,3)
Download Accelerator Plus - Find Free and DAP Premium Downloads
Download Accelerator Plus is available as both a free package and a paid Premium version. Download managers like Accelerator Plus and Premium better utilize the bandwidth of home network connections.
TCP Optimizer
This Windows utility automatically tunes your computer's TCP/IP network settings for improved performance.
TCP/IP Network Performance - Benchmarks and Tools
Utility software that measures TCP/IP performance at the application or protocol level can be helpful in benchmarking, troubleshooting and tuning of both local and Internet network connections. These five programs are among the most popular and proven benchmark tools for the job.
Netperf
An engineer at Hewlett-Packard developed Netperf to help the Unix network benchmarking community many years ago, and this benchmarking tool remains popular in Unix / Linux environments today.
NetSpec
NetSpec strives to implement more realistic network performance testing scenarios than the standard utilities by acocunting for variable traffic flows. NetSpec is an academic research project that includes source code.
zSB(3,3)
Nettest
Nettest is a simple latency and bendwidth performance benchmark for point-to-point TCP connections on Solaris and Linux.
TTCP
The Test TCP (TTCP) Benchmarking Tool measures network performance at the TCP and UDP level. Originally developed for Unix, TTCP has also been ported to Windows and other operating systems.
DBS - Distributed Benchmark System
The Distributed Benchmark System (DBS) is a performance benchmark tool for TCP/IP networks that attempts to expand on the capability of other tools in this category. DBS supports retransmission control and congestion avoidance performance evaluation across multiple dynamic connections.
Netperf
An engineer at Hewlett-Packard developed Netperf to help the Unix network benchmarking community many years ago, and this benchmarking tool remains popular in Unix / Linux environments today.
NetSpec
NetSpec strives to implement more realistic network performance testing scenarios than the standard utilities by acocunting for variable traffic flows. NetSpec is an academic research project that includes source code.
zSB(3,3)
Nettest
Nettest is a simple latency and bendwidth performance benchmark for point-to-point TCP connections on Solaris and Linux.
TTCP
The Test TCP (TTCP) Benchmarking Tool measures network performance at the TCP and UDP level. Originally developed for Unix, TTCP has also been ported to Windows and other operating systems.
DBS - Distributed Benchmark System
The Distributed Benchmark System (DBS) is a performance benchmark tool for TCP/IP networks that attempts to expand on the capability of other tools in this category. DBS supports retransmission control and congestion avoidance performance evaluation across multiple dynamic connections.
Introduction to Computer Network Speed
Bandwidth in computer networking refers to the data rate supported by a network connection or interface. Network bandwidth is not the only factor that contributes to the perceived speed of a network. A lesser known but other key element of network performance - latency - also plays an important role.
What Is Network Bandwidth?
Bandwidth is the primary measure of computer network speed. Virtually everyone knows the bandwidth rating of their modem or their Internet service that is prominently advertised on network products sold today.
In networking, bandwidth represents the overall capacity of the connection. The greater the capacity, the more likely that better performance will result. Bandwidth is the amount of data that passes through a network connection over time as measured in bps.
Bandwidth can refer to both actual and theoretical throughput, and it is important to distinguish between the two. For example, a standard dialup modem supports 56 Kbps of peak bandwidth, but due to physical limitations of telephone lines and other factors, a dialup connection cannot support more than 53 Kbps of bandwidth (about 10% less than maximum) in practice. Likewise a traditional Ethernet network theoretically supports 100 Mbps of bandwidth, but this maximum amount cannot reasonably be achieved due to overhead in the computer hardware and operating systems.
Broadband and Other High Bandwidth Connections
The term high bandwidth is sometimes used to distinguish faster broadband Internet connections from traditional dialup or cellular network speeds. Definitions vary, but high bandwidth connections generally support data rates of minimum 64 Kbps (and usually 300 Kbps or higher). Broadband is just one type of high bandwidth network communication method.
Measuring Network Bandwidth
Numerous tools exist for administrators to measure the bandwidth of network connections. On LANs (local area networks), these tools include netperf and ttcp. On the Internet, numerous bandwidth / speed test programs exist, most available for free online use.
Even with these tools at your disposal, bandwidth utilization is difficult to measure precisely as it varies over time depending on the configuration of hardware and characteristics of software applications including how they are being used.
What Is Network Bandwidth?
Bandwidth is the primary measure of computer network speed. Virtually everyone knows the bandwidth rating of their modem or their Internet service that is prominently advertised on network products sold today.
In networking, bandwidth represents the overall capacity of the connection. The greater the capacity, the more likely that better performance will result. Bandwidth is the amount of data that passes through a network connection over time as measured in bps.
Bandwidth can refer to both actual and theoretical throughput, and it is important to distinguish between the two. For example, a standard dialup modem supports 56 Kbps of peak bandwidth, but due to physical limitations of telephone lines and other factors, a dialup connection cannot support more than 53 Kbps of bandwidth (about 10% less than maximum) in practice. Likewise a traditional Ethernet network theoretically supports 100 Mbps of bandwidth, but this maximum amount cannot reasonably be achieved due to overhead in the computer hardware and operating systems.
Broadband and Other High Bandwidth Connections
The term high bandwidth is sometimes used to distinguish faster broadband Internet connections from traditional dialup or cellular network speeds. Definitions vary, but high bandwidth connections generally support data rates of minimum 64 Kbps (and usually 300 Kbps or higher). Broadband is just one type of high bandwidth network communication method.
Measuring Network Bandwidth
Numerous tools exist for administrators to measure the bandwidth of network connections. On LANs (local area networks), these tools include netperf and ttcp. On the Internet, numerous bandwidth / speed test programs exist, most available for free online use.
Even with these tools at your disposal, bandwidth utilization is difficult to measure precisely as it varies over time depending on the configuration of hardware and characteristics of software applications including how they are being used.
Tips for Troubleshooting Slow Internet Connections
This checklist describes common causes for slow Internet connections. A poor-performing connection can be caused by broadband router configuration issues, wireless interference, or any of several other technical issues with your home network. Follow these steps to diagnose slow Internet connections.
1). Broadband Router Settings
As the centerpiece of a network, a broadband router can be responsible for slow Internet connections if configured improperly. For example, the MTU setting of your router will lead to performance issues if set too high or too low. Ensure your router's settings are all consistent with the manufacturer's and your Internet Service Provider (ISP) recommendations. Carefully record any changes you make to your router's configuration so that you can undo them later if necessary.
2). Wireless Signal Interference
Wi-Fi and other types of wireless connections may perform poorly due to signal interference, which requires computers to continually resend messages to overcome signal issues. Household appliances and even your neighbors' wireless networks can interfere with your computers. To avoid slow Internet connections due to signal interference, reposition your router for better performance and change your Wi-Fi channel number.
3). Internet Worms
An Internet worm is a malicious software program that spreads through computer networks. If any of your computers are infected by an Internet worm, they may begin spontaneously generating network traffic without your knowledge, causing your Internet connection to appear slow. Run antivirus software regularly to diagnose and remove these worms from your computers.
4). Running Background Applications
Some software applications you install on a computer run in the background, quietly consuming network resources. Unlike worms, these are programs designed to do useful work. Peer to peer (P2P) programs in particular can heavily utilize your network and cause connections to appear slow. It's easy to forget these applications are running. Always check computers for any programs running in the background when troubleshooting a slow network.
5). Faulty Network Equipment
When routers, modems or cables fail, they typically won't support connections. Certain technical glitches in network equipment, however, adversely affect performance even though connections are maintained. To troubleshoot potentially faulty equipment, temporarily re-arrange and re-configure your gear while experimenting with different configurations. Try bypassing the router, swapping cables and changing network adapters to isolate the slow performance to a specific component of the system.
6). Service Provider Issues
Internet speed ultimately depends on the service provider. Your ISP may change their network's configuration, or suffer technical difficulties, that inadvertently cause your Internet connection to run slow. ISPs may also intentionally install filters or controls on the network that can lower your performance. Don't hesitate to contact your service provider if you suspect they are responsible for a slow Internet connection.
1). Broadband Router Settings
As the centerpiece of a network, a broadband router can be responsible for slow Internet connections if configured improperly. For example, the MTU setting of your router will lead to performance issues if set too high or too low. Ensure your router's settings are all consistent with the manufacturer's and your Internet Service Provider (ISP) recommendations. Carefully record any changes you make to your router's configuration so that you can undo them later if necessary.
2). Wireless Signal Interference
Wi-Fi and other types of wireless connections may perform poorly due to signal interference, which requires computers to continually resend messages to overcome signal issues. Household appliances and even your neighbors' wireless networks can interfere with your computers. To avoid slow Internet connections due to signal interference, reposition your router for better performance and change your Wi-Fi channel number.
3). Internet Worms
An Internet worm is a malicious software program that spreads through computer networks. If any of your computers are infected by an Internet worm, they may begin spontaneously generating network traffic without your knowledge, causing your Internet connection to appear slow. Run antivirus software regularly to diagnose and remove these worms from your computers.
4). Running Background Applications
Some software applications you install on a computer run in the background, quietly consuming network resources. Unlike worms, these are programs designed to do useful work. Peer to peer (P2P) programs in particular can heavily utilize your network and cause connections to appear slow. It's easy to forget these applications are running. Always check computers for any programs running in the background when troubleshooting a slow network.
5). Faulty Network Equipment
When routers, modems or cables fail, they typically won't support connections. Certain technical glitches in network equipment, however, adversely affect performance even though connections are maintained. To troubleshoot potentially faulty equipment, temporarily re-arrange and re-configure your gear while experimenting with different configurations. Try bypassing the router, swapping cables and changing network adapters to isolate the slow performance to a specific component of the system.
6). Service Provider Issues
Internet speed ultimately depends on the service provider. Your ISP may change their network's configuration, or suffer technical difficulties, that inadvertently cause your Internet connection to run slow. ISPs may also intentionally install filters or controls on the network that can lower your performance. Don't hesitate to contact your service provider if you suspect they are responsible for a slow Internet connection.
Thursday, November 19, 2009
Computer networking
Computer networking is the engineering discipline concerned with communication between computer systems or devices. Networking, routers, routing protocols, and networking over the public Internet have their specifications defined in documents called RFCs.
Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines.
There are three types of networks:
1.Internet.
2.Intranet.
3.Extranet.
A computer network is any set of computers or devices connected to each other with the ability to exchange data
Examples of different networks are:
1). Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.
2). Metropolitan area network (MAN), which is used for medium size area. examples for a city or a state.
3). Wide area network (WAN) that is usually a larger network that covers a large geographic
area.
4). Wireless LANs and WANs (WLAN & WWAN) are the wireless equivalent of the LAN and
WAN.
All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, power lines and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet.)
Computer networking is sometimes considered a sub-discipline of telecommunications, computer science, information technology and/or computer engineering. Computer networks rely heavily upon the theoretical and practical application of these scientific and engineering disciplines.
There are three types of networks:
1.Internet.
2.Intranet.
3.Extranet.
A computer network is any set of computers or devices connected to each other with the ability to exchange data
Examples of different networks are:
1). Local area network (LAN), which is usually a small network constrained to a small geographic area. An example of a LAN would be a computer network within a building.
2). Metropolitan area network (MAN), which is used for medium size area. examples for a city or a state.
3). Wide area network (WAN) that is usually a larger network that covers a large geographic
area.
4). Wireless LANs and WANs (WLAN & WWAN) are the wireless equivalent of the LAN and
WAN.
All networks are interconnected to allow communication with a variety of different kinds of media, including twisted-pair copper wire cable, coaxial cable, optical fiber, power lines and various wireless technologies. The devices can be separated by a few meters (e.g. via Bluetooth) or nearly unlimited distances (e.g. via the interconnections of the Internet.)
Computer network
A computer network is a group of computers that are connected to each other for the purpose of communication. Networks may be classified according to a wide variety of characteristics. This article provides a general overview of some types and categories and also presents the basic components of a network.
Introduction
A computer network allows computers to communicate with many other computers and to share resources and information. The Advanced Research Projects Agency (ARPA) funded the design of the "Advanced Research Projects Agency Network" (ARPANET) for the United States Department of Defense. It was the first operational computer network in the world.
Development of the network began in 1969, based on designs begun in the 1960s
Introduction
A computer network allows computers to communicate with many other computers and to share resources and information. The Advanced Research Projects Agency (ARPA) funded the design of the "Advanced Research Projects Agency Network" (ARPANET) for the United States Department of Defense. It was the first operational computer network in the world.
Development of the network began in 1969, based on designs begun in the 1960s
Views of networks
Users and network administrators often have different views of their networks. Often, users who share printers and some servers form a workgroup, which usually means they are in the same geographic location and are on the same LAN. A community of interest has less of a connection of being in a local area, and should be thought of as a set of arbitrarily located users who share a set of servers, and possibly also communicate via peer-to-peer technologies.
Network administrators see networks from both physical and logical perspectives.
The physical perspective involves geographic locations, physical cabling, and the network elements (e.g., routers, bridges and application layer gateways that interconnect the physical media. Logical networks, called, in the TCP/IP architecture, subnets, map onto one or more physical media. For example, a common practice in a campus of buildings is to make a set of LAN cables in each building appear to be a common subnet, using virtual LAN (VLAN) technology.
Both users and administrators will be aware, to varying extents, of the trust and scope characteristics of a network. Again using TCP/IP architectural terminology, an intranet is a community of interest under private administration usually by an enterprise, and is only accessible by authorized users (e.g. employees. Intranets do not have to be connected to the Internet, but generally have a limited connection.
An extranet is an extension of an intranet that allows secure communications to users outside of the intranet (e.g. business partners, customers.
Informally, the Internet is the set of users, enterprises,and content providers that are interconnected by Internet Service Providers (ISP). From an engineering standpoint, the Internet is the set of subnets, and aggregates of subnets, which share the registered IP address space and exchange information about the reachability of those IP addresses using the Border Gateway Protocol.
Typically, the human-readable names of servers are translated to IP addresses, transparently to users, via the directory function of the Domain Name System (DNS).
Over the Internet, there can be business-to-business (B2B), business-to-consumer (B2C) and consumer-to-consumer (C2C) communications. Especially when money or sensitive information is exchanged, the communications are apt to be secured by some form of communications security mechanism. Intranets and extranets can be securely superimposed onto the Internet, without any access by general Internet users, using secure Virtual Private Network (VPN) technology.
When used for gaming one computer will have to be the server while the others play through it.
Network administrators see networks from both physical and logical perspectives.
The physical perspective involves geographic locations, physical cabling, and the network elements (e.g., routers, bridges and application layer gateways that interconnect the physical media. Logical networks, called, in the TCP/IP architecture, subnets, map onto one or more physical media. For example, a common practice in a campus of buildings is to make a set of LAN cables in each building appear to be a common subnet, using virtual LAN (VLAN) technology.
Both users and administrators will be aware, to varying extents, of the trust and scope characteristics of a network. Again using TCP/IP architectural terminology, an intranet is a community of interest under private administration usually by an enterprise, and is only accessible by authorized users (e.g. employees. Intranets do not have to be connected to the Internet, but generally have a limited connection.
An extranet is an extension of an intranet that allows secure communications to users outside of the intranet (e.g. business partners, customers.
Informally, the Internet is the set of users, enterprises,and content providers that are interconnected by Internet Service Providers (ISP). From an engineering standpoint, the Internet is the set of subnets, and aggregates of subnets, which share the registered IP address space and exchange information about the reachability of those IP addresses using the Border Gateway Protocol.
Typically, the human-readable names of servers are translated to IP addresses, transparently to users, via the directory function of the Domain Name System (DNS).
Over the Internet, there can be business-to-business (B2B), business-to-consumer (B2C) and consumer-to-consumer (C2C) communications. Especially when money or sensitive information is exchanged, the communications are apt to be secured by some form of communications security mechanism. Intranets and extranets can be securely superimposed onto the Internet, without any access by general Internet users, using secure Virtual Private Network (VPN) technology.
When used for gaming one computer will have to be the server while the others play through it.
History of Computer Networks
Before the advent of computer networks that were based upon some type of[telecommunication]is system, communication between calculation machines and history of computer hardware early computers was performed by human users by carrying instructions between them. Many of the social behavior seen in today's Internet was demonstrably present in nineteenth-century and arguably in even earlier networks using visual signals. The Victorian Internet
In September 1940 George Stibitz used a teletype machine to send instructions for a problem set from his Model at Dartmouth College in New Hampshire to his Complex Number Calculator in New York and received results back by the same means. Linking output systems like teletypes to computers was an interest at the Advanced Research Projects Agency(ARPA) when, in 1962, J.C.R. Licklider was hired and developed a working group he called the "Intergalactic Network", a precursor to the ARPANet.
In 1964, researchers at Dartmouth developed the (Dartmouth Time Sharing System)for distributed users of large computer systems. The same year, at (MIT), a research group supported by General Electric and Bell Labs used a computer DEC's to route and manage telephone connections.
Throughout the 1960s Leonard Kleinrock,Paul Baran and Donald Davies independently conceptualized and developed network systems which used datagrams or Packet (information technology)that could be used in a network between computer systems.
1965 Thomas Merrill and Lawrence G. Roberts created the first wide area network (WAN).
The first widely used PSTN switch that used true computer control was the Western Electric introduced in 1965.
In 1969 the University of California at Los Angeles, SRI (in Stanford), University of California at Santa Barbara, and the University of Utah were connected as the beginning of the ARPANet network using 50 kbit/s circuits. Commercial services using X.25 were deployed in 1972, and later used as an underlying infrastructure for expanding TCP/IP networks.
Computer networks, and the technologies needed to connect and communicate through and between them, continue to drive computer hardware, software, and peripherals industries. This expansion is mirrored by growth in the numbers and types of users of networks from the researcher to the home user.
Today, computer networks are the core of modern communication. All modern aspects of the Public Switched Telephone Network(PSTN) are computer-controlled, and telephony increasingly runs over the Internet Protocol, although not necessarily the public Internet. The scope of communication has increased significantly in the past decade and this boom in communications would not have been possible without the progressively advancing computer network.
In September 1940 George Stibitz used a teletype machine to send instructions for a problem set from his Model at Dartmouth College in New Hampshire to his Complex Number Calculator in New York and received results back by the same means. Linking output systems like teletypes to computers was an interest at the Advanced Research Projects Agency(ARPA) when, in 1962, J.C.R. Licklider was hired and developed a working group he called the "Intergalactic Network", a precursor to the ARPANet.
In 1964, researchers at Dartmouth developed the (Dartmouth Time Sharing System)for distributed users of large computer systems. The same year, at (MIT), a research group supported by General Electric and Bell Labs used a computer DEC's to route and manage telephone connections.
Throughout the 1960s Leonard Kleinrock,Paul Baran and Donald Davies independently conceptualized and developed network systems which used datagrams or Packet (information technology)that could be used in a network between computer systems.
1965 Thomas Merrill and Lawrence G. Roberts created the first wide area network (WAN).
The first widely used PSTN switch that used true computer control was the Western Electric introduced in 1965.
In 1969 the University of California at Los Angeles, SRI (in Stanford), University of California at Santa Barbara, and the University of Utah were connected as the beginning of the ARPANet network using 50 kbit/s circuits. Commercial services using X.25 were deployed in 1972, and later used as an underlying infrastructure for expanding TCP/IP networks.
Computer networks, and the technologies needed to connect and communicate through and between them, continue to drive computer hardware, software, and peripherals industries. This expansion is mirrored by growth in the numbers and types of users of networks from the researcher to the home user.
Today, computer networks are the core of modern communication. All modern aspects of the Public Switched Telephone Network(PSTN) are computer-controlled, and telephony increasingly runs over the Internet Protocol, although not necessarily the public Internet. The scope of communication has increased significantly in the past decade and this boom in communications would not have been possible without the progressively advancing computer network.
Networking methods
One way to categorize computer networks is by their geographic scope, although many real-world networks interconnect Local Area Networks (LAN) via Wide Area Networks (WAN) and wireless networks (WWAN). These three (broad) types are:
Local area network (LAN)
A local area network is a network that spans a relatively small space and provides services to a small number of people.
A peer-to-peer or client-server method of networking may be used. A peer-to-peer network is where each client shares their resources with other workstations in the network. Examples of peer-to-peer networks are: Small office networks where resource use is minimal and a home network. A client-server network is where every client is connected to the server and each other. Client-server networks use servers in different capacities. These can be classified into two types:
1. Single-service servers
2. Print server
The server performs one task such as file server, while other servers can not only perform in the capacity of file servers and print servers, but also can conduct calculations and use them to provide information to clients (Web/Intranet Server). Computers may be connected in many different ways, including Ethernet cables, Wireless networks, or other types of wires such as power lines or phone lines.
The ITU-T G.hn standard is an example of a technology that provides high-speed (up to 1 Gbit/s) local area networking over existing home wiring (power lines, phone lines and coaxial cables).
Wide area network (WAN)
A wide area network is a network where a wide variety of resources are deployed across a large domestic area or internationally. An example of this is a multinational business that uses a WAN to interconnect their offices in different countries. The largest and best example of a WAN is the Internet, which is a network composed of many smaller networks. The Internet is considered the largest network in the world. The PSTN (Public Switched Telephone Network) also is an extremely large network that is converging to use Internet technologies, although not necessarily through the public Internet.
A Wide Area Network involves communication through the use of a wide range of different technologies. These technologies include Point-to-Point WANs such as Point-to-Point Protocol (PPP) and High-Level Data Link Control (HDLC), Frame Relay, ATM (Asynchronous Transfer Mode) and Sonet (Synchronous Optical Network). The difference between the WAN technologies is based on the switching capabilities they perform and the speed at which sending and receiving bits of information (data) occur.
Metropolitan area network (MAN)
A metropolitan network is a network that is too large for even the largest of LAN's but is not on the scale of a WAN. It also integrates two or more LAN networks over a specific geographical area ( usually a city ) so as to increase the network and the flow of communications. The LAN's in question would usually be connected via " backbone " lines.
For more information on WANs, see Frame Relay, ATM and Sonet.
Wireless networks (WLAN, WWAN)
A wireless network is basically the same as a LAN or a WAN but there are no wires between hosts and servers. The data is transferred over sets of radio transceivers. These types of networks are beneficial when it is too costly or inconvenient to run the necessary cables. For more information, see Wireless LAN and Wireless wide area network. The media access protocols for LANs come from the IEEE.
The most common IEEE 802.11 WLANs cover, depending on antennas, ranges from hundreds of meters to a few kilometers. For larger areas, either communications satellites of various types, cellular radio, or wireless local loop (IEEE 802.16) all have advantages and disadvantages. Depending on the type of mobility needed, the relevant standards may come from the IETF or the ITU.
Local area network (LAN)
A local area network is a network that spans a relatively small space and provides services to a small number of people.
A peer-to-peer or client-server method of networking may be used. A peer-to-peer network is where each client shares their resources with other workstations in the network. Examples of peer-to-peer networks are: Small office networks where resource use is minimal and a home network. A client-server network is where every client is connected to the server and each other. Client-server networks use servers in different capacities. These can be classified into two types:
1. Single-service servers
2. Print server
The server performs one task such as file server, while other servers can not only perform in the capacity of file servers and print servers, but also can conduct calculations and use them to provide information to clients (Web/Intranet Server). Computers may be connected in many different ways, including Ethernet cables, Wireless networks, or other types of wires such as power lines or phone lines.
The ITU-T G.hn standard is an example of a technology that provides high-speed (up to 1 Gbit/s) local area networking over existing home wiring (power lines, phone lines and coaxial cables).
Wide area network (WAN)
A wide area network is a network where a wide variety of resources are deployed across a large domestic area or internationally. An example of this is a multinational business that uses a WAN to interconnect their offices in different countries. The largest and best example of a WAN is the Internet, which is a network composed of many smaller networks. The Internet is considered the largest network in the world. The PSTN (Public Switched Telephone Network) also is an extremely large network that is converging to use Internet technologies, although not necessarily through the public Internet.
A Wide Area Network involves communication through the use of a wide range of different technologies. These technologies include Point-to-Point WANs such as Point-to-Point Protocol (PPP) and High-Level Data Link Control (HDLC), Frame Relay, ATM (Asynchronous Transfer Mode) and Sonet (Synchronous Optical Network). The difference between the WAN technologies is based on the switching capabilities they perform and the speed at which sending and receiving bits of information (data) occur.
Metropolitan area network (MAN)
A metropolitan network is a network that is too large for even the largest of LAN's but is not on the scale of a WAN. It also integrates two or more LAN networks over a specific geographical area ( usually a city ) so as to increase the network and the flow of communications. The LAN's in question would usually be connected via " backbone " lines.
For more information on WANs, see Frame Relay, ATM and Sonet.
Wireless networks (WLAN, WWAN)
A wireless network is basically the same as a LAN or a WAN but there are no wires between hosts and servers. The data is transferred over sets of radio transceivers. These types of networks are beneficial when it is too costly or inconvenient to run the necessary cables. For more information, see Wireless LAN and Wireless wide area network. The media access protocols for LANs come from the IEEE.
The most common IEEE 802.11 WLANs cover, depending on antennas, ranges from hundreds of meters to a few kilometers. For larger areas, either communications satellites of various types, cellular radio, or wireless local loop (IEEE 802.16) all have advantages and disadvantages. Depending on the type of mobility needed, the relevant standards may come from the IETF or the ITU.
Network topology
The network topology defines the way in which computers, printers, and other devices are connected, physically and logically. A network topology describes the layout of the wire and devices as well as the paths used by data transmissions.
Network topology has two types:
1) Physical
2) logical
Commonly used topologies include:
1). Bus
2). Star
3). Tree (hierarchical)
4). Linear
5). Ring
6). Mesh
partially connected
fully connected (sometimes known as fully redundant)
The network topologies mentioned above are only a general representation of the kinds of topologies used in computer network and are considered basic topologies.
As a matter of fact networking is defined by the standard of OSI (Open Systems Interconnection) reference for communications. The OSI model consists of seven layers. Each layer has its own function. The OSI model layers are Application, Presentation, Session, Transport, Network, Data Link, and Physical. The upper layers (Application, Presentation, Session) of the OSI model concentrate on the application while the lower layers (transport, network, data link, and physical) focus on signal flow of data from origin to destination.
The Application layer defines the medium that communications software and any applications need to communicate to other computers. Layer 6 which is the presentation layer focuses on defining data formats such as text, jpeg, gif, and binary. An example of this layer would be displaying a picture that was received in an e-mail. The 5th Layer is the session layer which establishes how to start, control, and end links or conversations. The transport layer includes protocols that allow it to provide functions in many different areas such as: error recovery, segmentation, and reassembly. The network layers primary job is the end to end delivery of data packets. To do this, the network layer relies on logical addressing so that the origin and destination point can both be recognized.
An example of this would be, ip running in a router’s job is to examine the destination address, compare the address to the ip routing table, separate the packet into smaller chunks for transporting purposes, and then deliver the packet to the correct receiver. Layer 2 is the data link layer, which sets the standards for data being delivered across a link or medium. The 1st layer is the physical layer which deals with the physical characteristics of the transmission of data such as the network card and network cable type. An easy way to remember the layers of OSI is to remember All People Seem To Need Data Processing (Layers 7 to 1).
Network topology has two types:
1) Physical
2) logical
Commonly used topologies include:
1). Bus
2). Star
3). Tree (hierarchical)
4). Linear
5). Ring
6). Mesh
partially connected
fully connected (sometimes known as fully redundant)
The network topologies mentioned above are only a general representation of the kinds of topologies used in computer network and are considered basic topologies.
As a matter of fact networking is defined by the standard of OSI (Open Systems Interconnection) reference for communications. The OSI model consists of seven layers. Each layer has its own function. The OSI model layers are Application, Presentation, Session, Transport, Network, Data Link, and Physical. The upper layers (Application, Presentation, Session) of the OSI model concentrate on the application while the lower layers (transport, network, data link, and physical) focus on signal flow of data from origin to destination.
The Application layer defines the medium that communications software and any applications need to communicate to other computers. Layer 6 which is the presentation layer focuses on defining data formats such as text, jpeg, gif, and binary. An example of this layer would be displaying a picture that was received in an e-mail. The 5th Layer is the session layer which establishes how to start, control, and end links or conversations. The transport layer includes protocols that allow it to provide functions in many different areas such as: error recovery, segmentation, and reassembly. The network layers primary job is the end to end delivery of data packets. To do this, the network layer relies on logical addressing so that the origin and destination point can both be recognized.
An example of this would be, ip running in a router’s job is to examine the destination address, compare the address to the ip routing table, separate the packet into smaller chunks for transporting purposes, and then deliver the packet to the correct receiver. Layer 2 is the data link layer, which sets the standards for data being delivered across a link or medium. The 1st layer is the physical layer which deals with the physical characteristics of the transmission of data such as the network card and network cable type. An easy way to remember the layers of OSI is to remember All People Seem To Need Data Processing (Layers 7 to 1).
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