Introduction to Telcommunication Cable
Here you will learn about submarine communication cable, amplifiers, repeaters, fiber optics ,telecommunicaion network and fiber optic cable companies. Submarine communication cables are the fiber optical cables and are used for the cross Atlantic communications. Submarine cables are consisting of fiber optics and electrical conductive tube that is used to transfer the electrical signals between the repeaters. Repeaters are the network communication and telecommunication devices that are used to amplify the signals.
Repeaters operate at the physical layer of the OSI layers model and work with the physical signals. Submarine fiber optical cables are less susceptible to failure and are very high transmission cables. Submarine fiber optical cables are usually laid 1m under the sea. A great research and planning is required to install the submarine fiber optic cables. Fiber optic cable is a light weight cable, 13 cm in diameter and consists of a bunch of glass fibers that are cable of transmitting the light. So the data is transferred at the speed of light through the fiber optic cables. Normally the submarine cables are not installed on the area where the fishing and ship activities are more.
Because ship anchor and shipping vessels can be the problem for the submarine cables. Submarine telecommunication cable is a cable that is used for the telecommunication between the countries across the world. With the passage of time, the submarine cables have advancements and new technologies and communication devices are being used in the telecommunication. Submarine telecommunication cables with the high amplifier can transmit data and signals at more than 5 GB per seconds. Submarine cables were first used for the telegraphic transmission between the countries, then for telephone and then for data communication.
Today, fiber optic submarine cable is the backbone of the whole internet. In case of any damage to the submarine cables the whole communication system can be greatly affected. The international cable protection committee was established in 1958 in London to protect the submarine cables.
This committee is funded by the member fiber optic cable operators and the main responsibilities of this committee to protect the submarine communication cable. Earlier telecommunication submarine cables were not using repeaters so there were great bandwidth problems. In 1980 fiber optical was developed it uses the optical amplifiers to transmit the signals at a very high speed. Submarine power cables are running for supplying the electrical power. Fishing, anchoring and shark fish bites can cause the damage to the cables and the damaged portion of the cable is brought to the surface for repairing purposes. The installation and the repairing cost of the submarine cables is very high. These cables are laid in the seabed by the cable lying ships. These ships are owned and operated by the wireless and big telecommunication companies around the world. The optical fibers in the fiber optic are used as a sensor to measure heat, pressure and temperature.
Fibers are made up of transparent plastic and glass to pass the light at a very high speed. Earthquakes are also the cause of the damage for the communication cables and a major Tsunami earthquake in December 2004, in the Indian Ocean caused big damages to the underlying telecommunication cables. Telecommunication cables have a large network across the world. Some of the major submarine cable companies of the world are Apollo, Pan American Crossing, Pacific Rim East, Japan-US, Columbus II, Columbus III, RJK, Eastern Caribbean fiber system and many other companies
Monday, February 14, 2011
Mobile Technology and Communications
Introduction to Mobile Technology and Communications
Here you will learn about mobile technologies, mobile phones, wireless communication introduction, overview to gsm, gprs, sms and mms reviews. A cellular or mobile phone is a long range portable electronic device for communication over long distance.
Current Mobile Phones can support many latest services such as SMS, GPRS, MMS, email, packet switching, WAP, Bluetooth and many more. Most of the mobile phones connect to the cellular networks and which are further connected with the PSTN (Public switching telephone network). Besides mobile communications, there is a wide range of mobile products available such mobile scanners, mobile printers and mobile labelers.
Mobile Network Technology
Mobile phones and their network vary very significantly from provider to provider and country to country. However the basic communication method of all of them is through the electromagnetic microwaves with a cell base station. The cellular companies have large antennas, which are usually mounted over towers, buildings and poles. The cell phones have low-power transceivers that transmit voice and data to the nearest sites usually within the 5 to 8 miles (8 to 13 kilometers away).
When a mobile device or phone is turned on, it registers with the mobile telephone exchange or switch. It is a unique identifier and is alerted by the mobile switch when there is an incoming phone call.
The handset listens for the strong signals from the nearest base stations. When a user moves, the mobile device handoff to various nearest sites during phone calls or while waiting between calls it reselect the nearest cell phone sites.
Cell sites have relatively less power radio transmitters. They broadcast their presence and relay communications between the mobile handsets and the switch. On the other hand, the switch connects the call to the same or another mobile network or subscriber.
The dialogue between the mobile phone handset and the cell phone site is a stream of the digital data, which includes the digitized audio. This technology depends on the same system as of mobile phone operator. Some mobile phone technologies have adopted the AMPS for the analog communication and D-AMPS, CDMA2000, EVDO, GSM, UMTS, and GPRS for the digital communication. Each mobile phone network has a unique radio frequency.
There are different mobile communication methods, such as SMS, WAP, WLAN, WIFI, GPRS, Bluetooth, Infrared, IrDA and I-Phone etc. Mobile phones are different from the cordless telephones because they only operate within the specific range. Many types of the mobile computers have been introduced including the Laptop computer, Subnotebook, Portable data terminal (PDT), Personal digital assistance (PDA), Tablet personal computer and smart phone.
Mobile phone features
Mobile phones have features beyond sending text messages and making the short or long distance voice calls, the other features including internet browsing, mp3 playback music, email, personal organizer, built in cameras, MMS, PPT, SMS, call registries, built in games, voice mails, downloading, video call, Bluetooth, infrared and they also serve as the wireless modem for a pc. In many countries of the world such as Australia, Pakistan, India, Maldives and Israel the incoming calls are free. However, in Canada, Hong Kong and the United states a person can be charged per minute for the incoming calls. Few mobile phones carriers in the United States are beginning to receive unlimited phone calls. Mobile technology has both negative and positive impact on every day’s life.
Health impact
Since the invention of the mobile phones many concerns have been raised about the potential health from the mobile phones. Study at the Danish Institute of cancer epidemiology does not show any link between cancer and mobile phone usage. This study only covers the analog phone usage till 1995. However the study by the International Agency for research on cancer shows link between cellular phone usage and tumor frequency.
Mobile dating
Mobile dating also known as cell dating and it allows users to chat, meet and possible involves in romance by SMS, chatting and the web. These services allow their subscribers to provide information about themselves in a short profile and which is stored in the cell phone sets as a dating ID. The users can search for the other IDS or call at a number given to them by the service. Users can find others with the criteria of age, location and gender. Most of these sites are free to use but the standard fees of SMS and dating service charges can apply per minute. Mobile dating websites focus attention on users that share the same social network and proximity.
Some cellular companies offer services such as homing device. This service alerts the users when someone is within the thirty feet of the user. Some cellular companies use Bluetooth technology to connect the users in the bars, clubs and social gatherings and this service is called proximity dating. These services are more popular in European countries, United States, Australia and Canada. Mobile dating websites are gaining popularity.
Mobile Learning
M-learning’ is the follow up of E-learning and which originates from D-learning (distance learning). M-learning is the delivery of education to the students who are not having fixed location or who prefer to use mobile phone technology for learning. The rapid growth in the mobile and communication sector make it possible to develop new forms of education. M-learning means delivery of education by means of the mobile phone devices, PDAs and audio players. M-learners seek the lessons in the small format.
Mobile software
Windows mobile, Palm OS and Symbian OS supports typical application binaries as found on the personal computers. Windows mobile also supports portable executable format which is associated with the .NET Framework. Both Windows Mobile and Palm OS provide free SDK and integrated development environment for the developers. BREW is another format which gives complete control of the handset and access to all its functions. Java (J2ME, Java ME) runs atop a virtual machine, which allows reasonable functionalities. Because of the extra security and compatibility, it is quite simple to write, distribute and execute the mobile Java applications.
Mobile Internet
According to the many sources, one of the major factors of the usage of mobile internet is its speed. Mobile internet has faster connection. Due to this fact, many users tend to use mobile internet. The introduction of the 3G cards has a competitive high speed. All the current service providers and trying to increase their bandwidth to get more customers. The numbers of mobile phones that are cable of surfing the net have been increasing rapidly. One of the greatest problems when browsing the net on the cell phones is the small size of the screen. Because of this many developers are developing the websites that can easily be seen on the cell phones as well.
Mobile society.
Ongoing debates about the cyberspace, e-computing and E-commerce have suggested that the online world somehow will be dramatically different from the life in the analog world. It is true that E-commerce continues to grow and the specific locations of the persons and businesses do not matter that much anyone. This is also true that now we are seeing forums, blogs, discussion groups and social network to re-socialize and form new tribes on the internet. It seems that everyday we are increasingly connected via technologies such as email, cellular phones, instant messaging and all of these technologies are increasingly interconnected with each other. When we communicate on our cell phones, we are also mobile in the sense that we can move freely while in the constant communication.
Here you will learn about mobile technologies, mobile phones, wireless communication introduction, overview to gsm, gprs, sms and mms reviews. A cellular or mobile phone is a long range portable electronic device for communication over long distance.
Current Mobile Phones can support many latest services such as SMS, GPRS, MMS, email, packet switching, WAP, Bluetooth and many more. Most of the mobile phones connect to the cellular networks and which are further connected with the PSTN (Public switching telephone network). Besides mobile communications, there is a wide range of mobile products available such mobile scanners, mobile printers and mobile labelers.
Mobile Network Technology
Mobile phones and their network vary very significantly from provider to provider and country to country. However the basic communication method of all of them is through the electromagnetic microwaves with a cell base station. The cellular companies have large antennas, which are usually mounted over towers, buildings and poles. The cell phones have low-power transceivers that transmit voice and data to the nearest sites usually within the 5 to 8 miles (8 to 13 kilometers away).
When a mobile device or phone is turned on, it registers with the mobile telephone exchange or switch. It is a unique identifier and is alerted by the mobile switch when there is an incoming phone call.
The handset listens for the strong signals from the nearest base stations. When a user moves, the mobile device handoff to various nearest sites during phone calls or while waiting between calls it reselect the nearest cell phone sites.
Cell sites have relatively less power radio transmitters. They broadcast their presence and relay communications between the mobile handsets and the switch. On the other hand, the switch connects the call to the same or another mobile network or subscriber.
The dialogue between the mobile phone handset and the cell phone site is a stream of the digital data, which includes the digitized audio. This technology depends on the same system as of mobile phone operator. Some mobile phone technologies have adopted the AMPS for the analog communication and D-AMPS, CDMA2000, EVDO, GSM, UMTS, and GPRS for the digital communication. Each mobile phone network has a unique radio frequency.
There are different mobile communication methods, such as SMS, WAP, WLAN, WIFI, GPRS, Bluetooth, Infrared, IrDA and I-Phone etc. Mobile phones are different from the cordless telephones because they only operate within the specific range. Many types of the mobile computers have been introduced including the Laptop computer, Subnotebook, Portable data terminal (PDT), Personal digital assistance (PDA), Tablet personal computer and smart phone.
Mobile phone features
Mobile phones have features beyond sending text messages and making the short or long distance voice calls, the other features including internet browsing, mp3 playback music, email, personal organizer, built in cameras, MMS, PPT, SMS, call registries, built in games, voice mails, downloading, video call, Bluetooth, infrared and they also serve as the wireless modem for a pc. In many countries of the world such as Australia, Pakistan, India, Maldives and Israel the incoming calls are free. However, in Canada, Hong Kong and the United states a person can be charged per minute for the incoming calls. Few mobile phones carriers in the United States are beginning to receive unlimited phone calls. Mobile technology has both negative and positive impact on every day’s life.
Health impact
Since the invention of the mobile phones many concerns have been raised about the potential health from the mobile phones. Study at the Danish Institute of cancer epidemiology does not show any link between cancer and mobile phone usage. This study only covers the analog phone usage till 1995. However the study by the International Agency for research on cancer shows link between cellular phone usage and tumor frequency.
Mobile dating
Mobile dating also known as cell dating and it allows users to chat, meet and possible involves in romance by SMS, chatting and the web. These services allow their subscribers to provide information about themselves in a short profile and which is stored in the cell phone sets as a dating ID. The users can search for the other IDS or call at a number given to them by the service. Users can find others with the criteria of age, location and gender. Most of these sites are free to use but the standard fees of SMS and dating service charges can apply per minute. Mobile dating websites focus attention on users that share the same social network and proximity.
Some cellular companies offer services such as homing device. This service alerts the users when someone is within the thirty feet of the user. Some cellular companies use Bluetooth technology to connect the users in the bars, clubs and social gatherings and this service is called proximity dating. These services are more popular in European countries, United States, Australia and Canada. Mobile dating websites are gaining popularity.
Mobile Learning
M-learning’ is the follow up of E-learning and which originates from D-learning (distance learning). M-learning is the delivery of education to the students who are not having fixed location or who prefer to use mobile phone technology for learning. The rapid growth in the mobile and communication sector make it possible to develop new forms of education. M-learning means delivery of education by means of the mobile phone devices, PDAs and audio players. M-learners seek the lessons in the small format.
Mobile software
Windows mobile, Palm OS and Symbian OS supports typical application binaries as found on the personal computers. Windows mobile also supports portable executable format which is associated with the .NET Framework. Both Windows Mobile and Palm OS provide free SDK and integrated development environment for the developers. BREW is another format which gives complete control of the handset and access to all its functions. Java (J2ME, Java ME) runs atop a virtual machine, which allows reasonable functionalities. Because of the extra security and compatibility, it is quite simple to write, distribute and execute the mobile Java applications.
Mobile Internet
According to the many sources, one of the major factors of the usage of mobile internet is its speed. Mobile internet has faster connection. Due to this fact, many users tend to use mobile internet. The introduction of the 3G cards has a competitive high speed. All the current service providers and trying to increase their bandwidth to get more customers. The numbers of mobile phones that are cable of surfing the net have been increasing rapidly. One of the greatest problems when browsing the net on the cell phones is the small size of the screen. Because of this many developers are developing the websites that can easily be seen on the cell phones as well.
Mobile society.
Ongoing debates about the cyberspace, e-computing and E-commerce have suggested that the online world somehow will be dramatically different from the life in the analog world. It is true that E-commerce continues to grow and the specific locations of the persons and businesses do not matter that much anyone. This is also true that now we are seeing forums, blogs, discussion groups and social network to re-socialize and form new tribes on the internet. It seems that everyday we are increasingly connected via technologies such as email, cellular phones, instant messaging and all of these technologies are increasingly interconnected with each other. When we communicate on our cell phones, we are also mobile in the sense that we can move freely while in the constant communication.
WAN Networking
WANs are used to connect the computers in the one part of the world with the other part of the world. So the users and computers from the different parts of the world can communicate with each other. Many WANs are generally built for one organization. Other types of WAN networking are the Internet service providers that connect the LANS or individual computers to the Internet. WAN networks are built using the leased lines and a router is connected to the one end of the WAN and a hub is connected to the other end.
With this hub a number of computers and other hubs and switches are connected. Among the other methods of building the WANs are the circuit switching or packet switching methods. The general protocols and the communication technologies that are involved in the overall wide area networking/communication are TCP/IP, SONET, MPLS, ATM and X.25, which closely works with frame relay. Typical a WAN consists of a number of interconnected switching nodes.
Networking Methods
Networking is a complex part of the computing and it covers the broader range of the IT industry. All the communication in the world including satellite communication, mobile communication, internet, telephones and WANs is due to the networking. There are two main types of the networking.
Local Area Network (LAN)
A local area network is relatively covers small space and provides services to a small amount of people. A local area can be divided into two major types, peer to peer and the client server. Depending on the number of the users a network is configured. Among the few examples of the peer to peer networks are small office network and home networks. On the other hand, in the client/server networking model all the client computers depends on the server for resources like (modem, printer, scanner, cd-rom) and they are connected with the server. The servers in the client/server networking model works in different capacities like single service server and multiple service servers.
Wide Area Network (WAN)
A wide area network is a network where are large number of the resources are deployed in a very wide geographically area. The best example of the WAN is the internet itself which is a largest network in the world.
In order for communication to take place between the computers the mediums must be used. These mediums can be cables, Routers, Repeaters, Ethernet, Protocols and switches etc. These different mediums make the data communication possible in different scenarios.
Types of WANs
There are two basic types of Widea Area Networking.
A computer network is set of computers and devices that are connected with each other. Examples of the networks are the Internet, local area network, Wide area network and satellite networks.
Centralized WANS:
A WAN that consists of a server or a group of servers in a central location to which client computers connect, the server provides the most of the functionalities of a network. Many banks, large stores, large schools and universities use centralized WAN. A centralized wide area network may have a number of the servers in the centralized location.
Distributed WAN:
A widea area network that consists of the client and server computers that are distributed throughout the WAN, the functionalities of the network are distributed throughout the WAN. The internet is an example of the wide area network.
The impact of Wide Area Networking on business
In this age of information, data communication (sending and receiving data) over a long distance is a necessity. There have been number of technologies developed that enable networks and their users to communicate with each other, and exchange data easily even if they are at the different end of the world. Geographical area is no more a matter in today’s communication age. Because of this the communication through WAN has been become vital. Wide area networks make it feasible for the companies to have a single network, which will connect their several offices and departments. Companies, banks, large organizations often have their offices spread over a large distance. Without wide area networking the people of a multinational organization can face difficulties to communicate with each. WANs are important in connecting institutes they are very far from each other.
Networking Methods
Networking is a complex part of the computing and it covers the broader range of the IT industry. All the communication in the world including satellite communication, mobile communication, internet, telephones and WANs is due to the networking. There are two main types of the networking.
Local Area Network (LAN)
A local area network is relatively covers small space and provides services to a small amount of people. A local area can be divided into two major types, peer to peer and the client server. Depending on the number of the users a network is configured. Among the few examples of the peer to peer networks are small office network and home networks. On the other hand, in the client/server networking model all the client computers depends on the server for resources like (modem, printer, scanner, cd-rom) and they are connected with the server. The servers in the client/server networking model works in different capacities like single service server and multiple service servers.
Wide Area Network (WAN)
A wide area network is a network where are large number of the resources are deployed in a very wide geographically area. The best example of the WAN is the internet itself which is a largest network in the world.
In order for communication to take place between the computers the mediums must be used. These mediums can be cables, Routers, Repeaters, Ethernet, Protocols and switches etc. These different mediums make the data communication possible in different scenarios.
Types of WANs
There are two basic types of Widea Area Networking.
A computer network is set of computers and devices that are connected with each other. Examples of the networks are the Internet, local area network, Wide area network and satellite networks.
Centralized WANS:
A WAN that consists of a server or a group of servers in a central location to which client computers connect, the server provides the most of the functionalities of a network. Many banks, large stores, large schools and universities use centralized WAN. A centralized wide area network may have a number of the servers in the centralized location.
Distributed WAN:
A widea area network that consists of the client and server computers that are distributed throughout the WAN, the functionalities of the network are distributed throughout the WAN. The internet is an example of the wide area network.
The impact of Wide Area Networking on business
In this age of information, data communication (sending and receiving data) over a long distance is a necessity. There have been number of technologies developed that enable networks and their users to communicate with each other, and exchange data easily even if they are at the different end of the world. Geographical area is no more a matter in today’s communication age. Because of this the communication through WAN has been become vital. Wide area networks make it feasible for the companies to have a single network, which will connect their several offices and departments. Companies, banks, large organizations often have their offices spread over a large distance. Without wide area networking the people of a multinational organization can face difficulties to communicate with each. WANs are important in connecting institutes they are very far from each other.
Web Server
What is a Web Server?
Learn Web server software overview, how to configure, how it works, apache, tomcat. Web server is a computer including a software package that provides the specific services to the client computers. Web server delivers the web pages. Every web server has an IP address and a domain name. If you sends a request through your browser for this website http://www.networktutorials.info, the request goes to the server whose domain name is networktutorials.info.
The server fetches the index or main page of the website and sends it to your browser. Web-based servers are used for hosting the websites. One web server can hosts thousands for one sites. But in the hosting companies there are number of the web servers for load balancing and sharing the other services.
The web hosting companies offer different types of hostings services including Ecommerce hosting, CPanel hosting, PHP hosting and reseller hosting.
A computer can be act as a web server by installing and configuring the server software and connecting the computer to the Internet. Normally, web server computers have to be turn on (online) for almost all the day.
There are many software applications that are used as the web server like IIS, Apache web server, Tom Cat web server. A web server typically accepts thousands of the concurrent incoming requests for the specific domain, that it hosts.
In case if the server is down for any reason, the websites that are hosted on this server cannot be accessed. So the downtime is a biggest negative thing for the web hosting companies. Many hosting companies have to mention the uptime of their servers for the client’s satisfactions like 99.9 % uptime. You may have seen this percentage on many hosting companies’ websites.
The web servers serves the objects in the form of html documents, plain text, images, sounds, video and some other form of the data. Many of the data types may not be placed in the static form but they are shown on the run time by the software programs, that are installed on the web server and the CGI scripts are the most common form of these programs.
Web servers and the browsers such as internet explorer, Firefox, Netscape, Opera etc communicate with the web server by using the HTTP protocols (Hypertext Transfer Protocol). This is very effective method of requesting the data over the Internet. Web servers are in various shapes and sized and run under different operating systems like Windows, Linux, and Unix etc. They are also range differently in prices and working.
Apache Web Server
The Apache web server is the most popular and most commonly used web server today. Apache web server has many features and good functionality that appeals to the users and that’s major cause of its popularity. On the other end, Microsoft’s IIS still is struggling to complete fully with apache web server. IIS is a very good server on the NT platforms and Apache is compatible with the Linux/Unix platforms.
Another big reason for the worldwide acceptance of the Apache web server is its stability. Many big websites on the Internet has chosen Apache web server for their hosting needs.
Additionally, Apache web server is a relatively fast. If your website contents are static then Apache’s working is very efficient and fast and on the other end, if you are using scripts like CGI scripts or others, it usually slows down the speed of the Apache web server.
A Web server is simply a little piece of the software, it takes the file name sent in the GET command, retrieves that files and send it back to the browser.
Most servers implement some level of security on the serving process. For example login/password accessible page requires the proper login and password from the users to accept that page. Web servers have the database and login information of the entire subscriber and only a subscriber of that typical service will be able to see that page. Additionally, while doing secure transactions the web pages allows encrypted transactions between the browsers and the servers such as on the E-commerce websites and other websites where a transaction through a credit card is required.
Basic Overview How Web Server Works
A web server performs various tasks on the request from the clients. To understand the working of the web server, it is necessary to first understand that what is client and server and what is their relationship with each other. A client is a program that sends request to a server and server responds to the requests of the clients.
This generic definition covers many types of relationships between client and servers like database server & web server etc. Web server have to be connected to the internet because client computers need to access them for various needs like data, files, graphics, video and html documents access.
The client program such as browsers and typically designed for the purpose of communicating with the web servers. A browser itself has different levels of features and security. To start the communication between the client (browser) and the server, a set of rules or agreed upon way is required and that is called a protocol. To access the web pages from the server HTTP protocol is required and for the file sharing access FTP protocol is required. There are a large number of the web protocols.
Learn Web server software overview, how to configure, how it works, apache, tomcat. Web server is a computer including a software package that provides the specific services to the client computers. Web server delivers the web pages. Every web server has an IP address and a domain name. If you sends a request through your browser for this website http://www.networktutorials.info, the request goes to the server whose domain name is networktutorials.info.
The server fetches the index or main page of the website and sends it to your browser. Web-based servers are used for hosting the websites. One web server can hosts thousands for one sites. But in the hosting companies there are number of the web servers for load balancing and sharing the other services.
The web hosting companies offer different types of hostings services including Ecommerce hosting, CPanel hosting, PHP hosting and reseller hosting.
A computer can be act as a web server by installing and configuring the server software and connecting the computer to the Internet. Normally, web server computers have to be turn on (online) for almost all the day.
There are many software applications that are used as the web server like IIS, Apache web server, Tom Cat web server. A web server typically accepts thousands of the concurrent incoming requests for the specific domain, that it hosts.
In case if the server is down for any reason, the websites that are hosted on this server cannot be accessed. So the downtime is a biggest negative thing for the web hosting companies. Many hosting companies have to mention the uptime of their servers for the client’s satisfactions like 99.9 % uptime. You may have seen this percentage on many hosting companies’ websites.
The web servers serves the objects in the form of html documents, plain text, images, sounds, video and some other form of the data. Many of the data types may not be placed in the static form but they are shown on the run time by the software programs, that are installed on the web server and the CGI scripts are the most common form of these programs.
Web servers and the browsers such as internet explorer, Firefox, Netscape, Opera etc communicate with the web server by using the HTTP protocols (Hypertext Transfer Protocol). This is very effective method of requesting the data over the Internet. Web servers are in various shapes and sized and run under different operating systems like Windows, Linux, and Unix etc. They are also range differently in prices and working.
Apache Web Server
The Apache web server is the most popular and most commonly used web server today. Apache web server has many features and good functionality that appeals to the users and that’s major cause of its popularity. On the other end, Microsoft’s IIS still is struggling to complete fully with apache web server. IIS is a very good server on the NT platforms and Apache is compatible with the Linux/Unix platforms.
Another big reason for the worldwide acceptance of the Apache web server is its stability. Many big websites on the Internet has chosen Apache web server for their hosting needs.
Additionally, Apache web server is a relatively fast. If your website contents are static then Apache’s working is very efficient and fast and on the other end, if you are using scripts like CGI scripts or others, it usually slows down the speed of the Apache web server.
A Web server is simply a little piece of the software, it takes the file name sent in the GET command, retrieves that files and send it back to the browser.
Most servers implement some level of security on the serving process. For example login/password accessible page requires the proper login and password from the users to accept that page. Web servers have the database and login information of the entire subscriber and only a subscriber of that typical service will be able to see that page. Additionally, while doing secure transactions the web pages allows encrypted transactions between the browsers and the servers such as on the E-commerce websites and other websites where a transaction through a credit card is required.
Basic Overview How Web Server Works
A web server performs various tasks on the request from the clients. To understand the working of the web server, it is necessary to first understand that what is client and server and what is their relationship with each other. A client is a program that sends request to a server and server responds to the requests of the clients.
This generic definition covers many types of relationships between client and servers like database server & web server etc. Web server have to be connected to the internet because client computers need to access them for various needs like data, files, graphics, video and html documents access.
The client program such as browsers and typically designed for the purpose of communicating with the web servers. A browser itself has different levels of features and security. To start the communication between the client (browser) and the server, a set of rules or agreed upon way is required and that is called a protocol. To access the web pages from the server HTTP protocol is required and for the file sharing access FTP protocol is required. There are a large number of the web protocols.
Introduction to Internet
The most common use of the internet is the World Wide Web (WWW) and the most important feature of the WWW is HTTP (hypertext transfer protocol). This protocol is used to view the html documents in the web browsers. TCP/IP (transmission control protocol/internet protocol) is the protocol that is used for communication in the internet. Every computer which is connected with the internet has a unique identifier which is known as IP address. An IP address is a 32 bits decimal numbers address such as 10.11.11.1, 112.1.1.30 etc.
There are certain marketing methods on the internet that are used to promote a business such as search engines marketing methods, email marketing, banner exchanges, directory submission, articles writing and promoting and many other types. Today researches can share their knowledge and experiences with their fellow researchers around the world, which was not easy before the internet. Internet is also a source of distance learning education system, in which a student is enrolled in a specific course on the internet, no matter what the geographic location of the student is. Internet connection is easily available to everyone who has a computer, fax modem and a telephone line. Upon connecting with the local ISPs, we can connect with every available computer on the internet.
There are certain other advantages of the internet such as video conferencing, telemarketing, telemedicine, call centers, VOIP and web conferencing. Advance education and new research was not available so fast to everyone before the internet. The communication on the internet is carried out by a device known as a router. A router is a communication device which has a built inn routing table and with this routing table the destinations of the data is determined. Routing on the internet is a method of communication that uses physical address, selection of the gateway and the numerical address of the computer or routers.
Technically, internet is consisting of a large number of the interconnected autonomous systems. The most commonly used protocols by the routers are RIP and OSPF. Both the packet switching and IP networks provide the way, which routing protocols use for the communication on the internet. There are certain dedicated computers on the internet that are available online 24 hours and provide certain types of services. Internet also facilitates us for online bookings in the airlines and trains. Many companies uses internet as a medium to connect with the other private networks of the same company. Many universities and colleges use internet to form their private intranet, in which only authorized persons can access the private resources of an organization or university.
Finally, internet is a largest learning and information sharing portal on this planet in which many people from all over the world get connected with each other at the same time and can communication in a number of ways.
Satellite Communication Technology
Most of the communication today from Satellite TV Channels to GPS and Inter Country Communication to GPS runs on Satellites. Satellites are man made devices that revolve around the earth’s orbit for specific purposes. Satellites have made our life a whole lot easier. The main reason for this is that satellites do cover a huge geographical section of earth and this is the reason why a single satellite employed in earth’s orbit can serve a lot of users at the same time.
Satellites move in round orbits. A satellite’s orbit can not be elliptical around the earth. There are three types of satellites around the earth’s orbit according to the distance from earth.
The types are LEO (Lower Earth Orbit), MEO (Medium Earth Orbit) and GEO (Geo Stationary Earth Orbit). In Lower Earth Orbit, the satellite moves at 315 to 350 kilo meters above the earth’s orbit. In LEO, 45 satellites are required to cover the complete earth’s orbit. At any given point, 3 or 4 satellites are accessible from any point on earth.
In MEO, a satellite is around 19,000 kilometers around earth’s orbit. The examples of medium earth orbit satellites are weather satellites that record the Earth’s atmospheric changes and send them to earth.
The most important are Geo Stationary Earth Orbits, also known as GEO Satellites. These satellites revolve around the earth in complete synchronization with the earth’s movement around itself.
GEO Satellites are exactly 35,786 kilometers around the earth’s orbit. These satellites revolve exactly at the same speed as our earth and seem stationary in their orbit. Due to their height from earth, they seem like at the same position and do not deviate from their path. Satellite channels are transmitted from GEO satellites. 3 – 4 GEO Satellites can cover the complete earth’s crust and cover a huge geographical area.
Satellites play a key role in communication around the earth. The most essential part of earth centric satellites is their power system. All the satellites have huge wings which contain solar cells. The satellites use the sun’s solar energy to power them and perform every day routine activities. Satellites have two frequencies. One is uplink and the other is downlink. Satellite takes the uplink in the form of a beam pointing towards it and it spreads the rays downwards with a downlink frequency. In the middle time, it modulates and demodulates the frequency spectrum and performs specific functions on the data.
The other important part of the satellite is propulsion sub system. Propulsion subsystem is responsible to keep the satellite in its orbit. Whenever the satellite deviates from its original orbit, the rocket fuel in the Satellite’s Propulsion subsystem propels the rocket to come in the correct orbit. This is the reason, why satellites have an average life of 8 – 10 years because the amount of rocket fuel isn’t too much to support for ever.
Satellites move in round orbits. A satellite’s orbit can not be elliptical around the earth. There are three types of satellites around the earth’s orbit according to the distance from earth.
The types are LEO (Lower Earth Orbit), MEO (Medium Earth Orbit) and GEO (Geo Stationary Earth Orbit). In Lower Earth Orbit, the satellite moves at 315 to 350 kilo meters above the earth’s orbit. In LEO, 45 satellites are required to cover the complete earth’s orbit. At any given point, 3 or 4 satellites are accessible from any point on earth.
In MEO, a satellite is around 19,000 kilometers around earth’s orbit. The examples of medium earth orbit satellites are weather satellites that record the Earth’s atmospheric changes and send them to earth.
The most important are Geo Stationary Earth Orbits, also known as GEO Satellites. These satellites revolve around the earth in complete synchronization with the earth’s movement around itself.
GEO Satellites are exactly 35,786 kilometers around the earth’s orbit. These satellites revolve exactly at the same speed as our earth and seem stationary in their orbit. Due to their height from earth, they seem like at the same position and do not deviate from their path. Satellite channels are transmitted from GEO satellites. 3 – 4 GEO Satellites can cover the complete earth’s crust and cover a huge geographical area.
Satellites play a key role in communication around the earth. The most essential part of earth centric satellites is their power system. All the satellites have huge wings which contain solar cells. The satellites use the sun’s solar energy to power them and perform every day routine activities. Satellites have two frequencies. One is uplink and the other is downlink. Satellite takes the uplink in the form of a beam pointing towards it and it spreads the rays downwards with a downlink frequency. In the middle time, it modulates and demodulates the frequency spectrum and performs specific functions on the data.
The other important part of the satellite is propulsion sub system. Propulsion subsystem is responsible to keep the satellite in its orbit. Whenever the satellite deviates from its original orbit, the rocket fuel in the Satellite’s Propulsion subsystem propels the rocket to come in the correct orbit. This is the reason, why satellites have an average life of 8 – 10 years because the amount of rocket fuel isn’t too much to support for ever.
Wireless Networking
Here you will find wireless networking tutorials, what is wifi, general security overview, wlans, wpans, wmans, wep and wireless access control overview. Whether you want to make a phone call from your mobile, received a message on your pager, checked your email from a PDA we have come across a wireless data or voice network.
If a user or a company wants to make a data portable then Wireless networking is the answer. A wireless networking system can avoid the downtime, which may be caused in the wired network. A wireless network is also save your time and efforts in installing the lot of cables.
Also, if you need to relocate a client machine in your office, you only need to move the computer with wireless network card.
Wireless networking is very useful in the public places, libraries, hotels, schools, airports, railway stations where one might find wireless access to the internet. A drawback in the wireless internet is that quality of service (QOS) is not guaranteed if there is any interference then the connection may be dropped.
Wireless Network Types
Wireless Local Area Networks (WLANS)
WLANS allow users in local area, such as in a university or a library to form a network and gain wireless access to the internet. A temporary network can be formed by a small number of users without the need of access point; given that they do not need to access the resources.
Wireless Personal Area Networks (WPANS)
There are two current technologies for wireless personal network Bluetooth and Infra Red. These technologies will allow the connectivity of personal devices within an area of 30 feet. Infra Red requires a direct line and the range is less as compared to Bluetooth technology.
Wireless Metropolitan Area Networks (WMANS)
WMANS allow the connectivity of multiple networks in a metropolitan area such as building in a city. The network connectivity is the alternative of copper or fiber cabling.
Wireless Wide Area Networks (WWANS)
WWANS or Wireless Area Networks can be maintained over large areas such as in different cities or between different countries, via multiple satellite systems or antenna sites. The types of system are called 2G systems.
The following table shows the range those different types of wireless network covers.
Network Meter
Personal Area Network 0-10
Local Area Network 0-100
Wide Are Network 0-10000
Security in Wireless Networking
The following different types of security methods are available in the wireless networking.
Wired Equivalent Privacy (WEP)
Wired Equivalent Privacy is intended to stop the interference of radio frequency that is signaled by unauthorized users and this security measure is most suitable for the small networks. There is not key management protocol and each key is entered manually into the clients that’s why this is very time consuming administrative task. The WEP security method is based on the RC4 encryption algorithm. In the WEP all the client computers and Access points are configured with the same encryption and decryption keys.
Service Set Identifier (SSID)
Service Set Identifier (SSID) acts a simple password by allowing WLAN network to be split up into different networks and each having a unique identifier. These identifiers are configured in the multiple access points. To access any of any networks, a computer is configured in such a way that each is having a corresponding SSID identifier for that network. If the SSID match between the two computers or networks then access is granted to each other.
Media Access Control filtering (MAC Access Control)
A list of the MAC addresses of the client computers can be inputted into an Access point and only those computers are granted to give the access to the network. When a computer makes a request, its MAC address is compared to the list of the MAC addresses to the Access point and based on this access permission granted to deny.
This is a good security method but it is mainly involved in the small wireless networks because there is more manual work is involved of entering the MAC address into the Access point.
Bluetooth
Bluetooth is a simple type of the wireless networking that operates in the digital devices, like mobiles phones, personal computers, PDA, Laptops, digital camera, MP3 players and other Bluetooth enabled devices to form a small network. In the Bluetooth technology eight devices can be connected to each other at the same time. Bluetooth can also be found in the headsets, hands-free kits, wireless keyboards and mouse. Bluetooth technology was invented by Ericsson in 1994 and after four years in 1998 some major mobile phone companies such as Nokia, Ericsson, Intel and Toshiba formed a group to promote this technology.
Bluetooth technology falls in the category of personal area networking because it operates in the range of 30 to 300 feet. Bluetooth uses the radio waves technology, which is not very expensive and has low power consumption. Many different companies are intended to add the Bluetooth chip in their digital devices. Bluetooth technology is getting very popularity because of its low cost and portability.
The Future of Wireless Networking
WLANS wireless networking type is very popular in home networking and more than 20 percent homes with broadband internet are using WLANS and this number is increasing. In a general estimate worldwide hotspots have now reached more than 30,000 and will grow about 210,000 in the next few years. Most large hotels already offer Wi-Fi and the business travelers are willing to pay wireless access. 802.11 is the next Wi-Fi speed standard is set to offer bandwidth around 108Mbps and is still under development. With the speed of 70 Mbps and a range up to 30 miles, the 80216 standard, known as WiMAX is sure to get boost.
Some Tips & Tricks
• When purchasing a wireless NIC card try to get one that is having external antenna. When you are out and using Wi-Fi enabled laptop, disable Microsoft file and sharing, which enables other computers in a network to access data and resources on your computer. In this way, your computer or laptop will be saved from hackers.
• If you are concerned about the interference from the other wireless access point set the AP and wireless computers to use a non-overlapping channel.
• Change the configuration interface password of the access point before you enable it.
• Only buy an access point that is having upgradeable capabilities. By this way you can take the advantage of security enhancements.
• Keep the access point up to date.
If a user or a company wants to make a data portable then Wireless networking is the answer. A wireless networking system can avoid the downtime, which may be caused in the wired network. A wireless network is also save your time and efforts in installing the lot of cables.
Also, if you need to relocate a client machine in your office, you only need to move the computer with wireless network card.
Wireless networking is very useful in the public places, libraries, hotels, schools, airports, railway stations where one might find wireless access to the internet. A drawback in the wireless internet is that quality of service (QOS) is not guaranteed if there is any interference then the connection may be dropped.
Wireless Network Types
Wireless Local Area Networks (WLANS)
WLANS allow users in local area, such as in a university or a library to form a network and gain wireless access to the internet. A temporary network can be formed by a small number of users without the need of access point; given that they do not need to access the resources.
Wireless Personal Area Networks (WPANS)
There are two current technologies for wireless personal network Bluetooth and Infra Red. These technologies will allow the connectivity of personal devices within an area of 30 feet. Infra Red requires a direct line and the range is less as compared to Bluetooth technology.
Wireless Metropolitan Area Networks (WMANS)
WMANS allow the connectivity of multiple networks in a metropolitan area such as building in a city. The network connectivity is the alternative of copper or fiber cabling.
Wireless Wide Area Networks (WWANS)
WWANS or Wireless Area Networks can be maintained over large areas such as in different cities or between different countries, via multiple satellite systems or antenna sites. The types of system are called 2G systems.
The following table shows the range those different types of wireless network covers.
Network Meter
Personal Area Network 0-10
Local Area Network 0-100
Wide Are Network 0-10000
Security in Wireless Networking
The following different types of security methods are available in the wireless networking.
Wired Equivalent Privacy (WEP)
Wired Equivalent Privacy is intended to stop the interference of radio frequency that is signaled by unauthorized users and this security measure is most suitable for the small networks. There is not key management protocol and each key is entered manually into the clients that’s why this is very time consuming administrative task. The WEP security method is based on the RC4 encryption algorithm. In the WEP all the client computers and Access points are configured with the same encryption and decryption keys.
Service Set Identifier (SSID)
Service Set Identifier (SSID) acts a simple password by allowing WLAN network to be split up into different networks and each having a unique identifier. These identifiers are configured in the multiple access points. To access any of any networks, a computer is configured in such a way that each is having a corresponding SSID identifier for that network. If the SSID match between the two computers or networks then access is granted to each other.
Media Access Control filtering (MAC Access Control)
A list of the MAC addresses of the client computers can be inputted into an Access point and only those computers are granted to give the access to the network. When a computer makes a request, its MAC address is compared to the list of the MAC addresses to the Access point and based on this access permission granted to deny.
This is a good security method but it is mainly involved in the small wireless networks because there is more manual work is involved of entering the MAC address into the Access point.
Bluetooth
Bluetooth is a simple type of the wireless networking that operates in the digital devices, like mobiles phones, personal computers, PDA, Laptops, digital camera, MP3 players and other Bluetooth enabled devices to form a small network. In the Bluetooth technology eight devices can be connected to each other at the same time. Bluetooth can also be found in the headsets, hands-free kits, wireless keyboards and mouse. Bluetooth technology was invented by Ericsson in 1994 and after four years in 1998 some major mobile phone companies such as Nokia, Ericsson, Intel and Toshiba formed a group to promote this technology.
Bluetooth technology falls in the category of personal area networking because it operates in the range of 30 to 300 feet. Bluetooth uses the radio waves technology, which is not very expensive and has low power consumption. Many different companies are intended to add the Bluetooth chip in their digital devices. Bluetooth technology is getting very popularity because of its low cost and portability.
The Future of Wireless Networking
WLANS wireless networking type is very popular in home networking and more than 20 percent homes with broadband internet are using WLANS and this number is increasing. In a general estimate worldwide hotspots have now reached more than 30,000 and will grow about 210,000 in the next few years. Most large hotels already offer Wi-Fi and the business travelers are willing to pay wireless access. 802.11 is the next Wi-Fi speed standard is set to offer bandwidth around 108Mbps and is still under development. With the speed of 70 Mbps and a range up to 30 miles, the 80216 standard, known as WiMAX is sure to get boost.
Some Tips & Tricks
• When purchasing a wireless NIC card try to get one that is having external antenna. When you are out and using Wi-Fi enabled laptop, disable Microsoft file and sharing, which enables other computers in a network to access data and resources on your computer. In this way, your computer or laptop will be saved from hackers.
• If you are concerned about the interference from the other wireless access point set the AP and wireless computers to use a non-overlapping channel.
• Change the configuration interface password of the access point before you enable it.
• Only buy an access point that is having upgradeable capabilities. By this way you can take the advantage of security enhancements.
• Keep the access point up to date.
How to Configure a Network
In this section you will learn how to configure a network, peer to peer, client server, workstation, server, basic data communication.
Peer to Peer network model
Before configuring a computer network, you have to decide that, which networking model you require. There are two main types of network models. Peer to peer and client-server network model. In the peer to peer network model you simply use the same Workgroup for all the computers and a unique name for each computer.
Additionally, you will have to give a unique IP address of the same class A, B, or C for all the computers in your network and its related subnet mask e.g if you decide to use class A IP address for your three computers in your Peer to Peer network then your IP address/Subnet mask settings can be as follows.
Computer Name IP Address Subnet Mask Workgroup
PC1 100.100.100.1 255.0.0.0 Officenetwork
PC2 100.100.100.2 255.0.0.0 Officenetwork
PC3 100.100.100.3 255.0.0.0 Officenetwor
illustration purpose so you can choose any IP address, computer name and workgroup name of your interest.
For doing this right click on My Computer and then click Properties then go to the Network Identification section and set these.
In a peer to peer network all computers acts as a client because there is not centralized server. Peer to peer network is used where not security is required in the network.
If a computer fails to work then all other computers work normally in peer to peer network.
Client/Server Network Model
In the client/server network model a computer plays a centralized role and is known as a server all other computers in the network are known as clients. All client computers access the server simultaneously for files, database, docs, spreadsheets, web pages and resources like hard diver, printer, fax modem, CD/DVD ROM and others. In other words, all the client computes depends on the server and if server fails to respond or crash then networking/communication between the server and the client computes stops.
If you want to configure a client-server network model then first prepare the server. Install Windows 2000 or Windows 2003 Server from the CD on the server computer and make a domain. You can create a domain by this command on the Run “DCPROMO”. You can give this command once you install the server successfully. After you give the DCPROMO command you will be asked for a unique domain name. All the client computers will use the same unique domain name for becoming the part of this domain. This command will install the active directory on the server, DNS and other required things. A step by step wizard will run and will guide you for the rest of the steps. Make sure that a network cable is plugged in the LAN card of the server when you run the DCPROMO.exe command.
When the Active directory is properly installed on the server, restart the server. You can create network users on the server computer and also name/label the network resources like computers/printers etc.
Once you install the server successfully now come to the client computers. Install Windows 2000 professional on your all client computers. Once you install the Windows 2000 professional on the clients the next step is to make this computer (client computer) a part of the network.
Configuration Steps
1. Choose a unique name for each client computer
2. Choose unique IP address for each computer and relevant.
3. Use the same domain name for all client PCs.
Network/System administrators are required to do these administrative tasks on the server and client computers. Any shared resources on the network either on the server or the clients can be access through the My Network Places in the Windows 2000 platform. There is another way to connect to the shared resources by giving this command in the run \\ComputerName\SharedDriveLetter.
Network configurations steps can be implemented by right clicking the My Computer>Properties>
For giving the IP address you will have to right click on the My Network places>properties>Local Area Connection>Properties>Internet Protocols (TCP/IP)>Properties and then give the IP address and subnet mask of the same range and class for all the computers in the network.
Peer to Peer network model
Before configuring a computer network, you have to decide that, which networking model you require. There are two main types of network models. Peer to peer and client-server network model. In the peer to peer network model you simply use the same Workgroup for all the computers and a unique name for each computer.
Additionally, you will have to give a unique IP address of the same class A, B, or C for all the computers in your network and its related subnet mask e.g if you decide to use class A IP address for your three computers in your Peer to Peer network then your IP address/Subnet mask settings can be as follows.
Computer Name IP Address Subnet Mask Workgroup
PC1 100.100.100.1 255.0.0.0 Officenetwork
PC2 100.100.100.2 255.0.0.0 Officenetwork
PC3 100.100.100.3 255.0.0.0 Officenetwor
illustration purpose so you can choose any IP address, computer name and workgroup name of your interest.
For doing this right click on My Computer and then click Properties then go to the Network Identification section and set these.
In a peer to peer network all computers acts as a client because there is not centralized server. Peer to peer network is used where not security is required in the network.
If a computer fails to work then all other computers work normally in peer to peer network.
Client/Server Network Model
In the client/server network model a computer plays a centralized role and is known as a server all other computers in the network are known as clients. All client computers access the server simultaneously for files, database, docs, spreadsheets, web pages and resources like hard diver, printer, fax modem, CD/DVD ROM and others. In other words, all the client computes depends on the server and if server fails to respond or crash then networking/communication between the server and the client computes stops.
If you want to configure a client-server network model then first prepare the server. Install Windows 2000 or Windows 2003 Server from the CD on the server computer and make a domain. You can create a domain by this command on the Run “DCPROMO”. You can give this command once you install the server successfully. After you give the DCPROMO command you will be asked for a unique domain name. All the client computers will use the same unique domain name for becoming the part of this domain. This command will install the active directory on the server, DNS and other required things. A step by step wizard will run and will guide you for the rest of the steps. Make sure that a network cable is plugged in the LAN card of the server when you run the DCPROMO.exe command.
When the Active directory is properly installed on the server, restart the server. You can create network users on the server computer and also name/label the network resources like computers/printers etc.
Once you install the server successfully now come to the client computers. Install Windows 2000 professional on your all client computers. Once you install the Windows 2000 professional on the clients the next step is to make this computer (client computer) a part of the network.
Configuration Steps
1. Choose a unique name for each client computer
2. Choose unique IP address for each computer and relevant.
3. Use the same domain name for all client PCs.
Network/System administrators are required to do these administrative tasks on the server and client computers. Any shared resources on the network either on the server or the clients can be access through the My Network Places in the Windows 2000 platform. There is another way to connect to the shared resources by giving this command in the run \\ComputerName\SharedDriveLetter.
Network configurations steps can be implemented by right clicking the My Computer>Properties>
For giving the IP address you will have to right click on the My Network places>properties>Local Area Connection>Properties>Internet Protocols (TCP/IP)>Properties and then give the IP address and subnet mask of the same range and class for all the computers in the network.
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