A proxy server has two main purposes:
- To keep machines behind it anonymous. It's really help us to keep our privacy and network security.
- To speed up access to a resource (via caching). It is commonly used to cache web pages from a web server.
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Wednesday, August 19, 2009
What is Proxy means
In computer networks, a proxy server is a server, that could be a computer system or an application program that acts as a go-between for requests from clients seeking resources from other servers. In other word, proxy server called man in the midle between real server on internet and the client. Simple work from a proxy server, client connects to server, requesting some service, such as a file, connection, web page, or other resource, available from a different server that allocate on other network. The proxy server evaluates the request according to its filtering rules. For example, it may filter traffic by protocol, time access, or IP address. If the request is validated by the filter, the proxy provides the resource by connecting to the relevant server and requesting the service on behalf of the client. A proxy server may optionally alter the client's request or the server's response, and sometimes it may serve the request without contacting the specified server. In this case, it 'caches' responses from the remote server, and returns subsequent requests for the same content directly. With this use, our connection to internet will be more simple because we didn't need to contact the real server to have what we want. We can set our proxy server to update the data to synchronous with the real server.
A proxy server has two main purposes:
A proxy server has two main purposes:
Friday, August 7, 2009
Collaboration between Facebook with Twitter
We all know Facebook is a most growth social networking in internet. It's connect so many people so easily and make a distance has no meaning. Also with Twitter, this is a mini blog with high growing rate as well as Facebook does. Now we will make a collaboration between this two powerfull site. We will make an update from Facebook will be appear in our Twitter homepage and vice versa.
Both Facebook and Twitter have pretty extensive APIs that you can develop applications against. With these a lot is certainly possible, but it would take development time and effort to write the code necessary to accomplish whatever else you might want to do. Also keep in mind that "everything" isn't possible. The APIs are limited in certain respects, specially where privacy, technical, or other issues might be involved.
- Facebook make an update to Twitter
First, find your status RSS feed on Facebook. It is buried. To find it, we need to visit our profile and on our mini-feed select "See All". On the right you will see a list of items, select “status stories” and finally below this a feed link can be found. Finally add your newly found status RSS feed to the TwitterFeed service. In this step, we can set our update frequentcy, prefixed it with "From Facebook..." and am publishing just the title from the status feed. - Twitter make an update to Facebook
The official Twitter Facebook app (found here: http://apps.facebook.com/twitter/) has an option after you install it to update your Facebook status with your latest tweet. We need to understand that there is a delay if you use twitter frequently. But overall it's really powerfull to make frequently update for both with one update in a side.
Both Facebook and Twitter have pretty extensive APIs that you can develop applications against. With these a lot is certainly possible, but it would take development time and effort to write the code necessary to accomplish whatever else you might want to do. Also keep in mind that "everything" isn't possible. The APIs are limited in certain respects, specially where privacy, technical, or other issues might be involved.
Sunday, March 1, 2009
What is set associative mapping
set associative cache - A compromise between a direct mapped cache and a fully associative cache where each address is mapped to a certain set of cache locations. The address space is divided into blocks of 2^m bytes (the cache line size), discarding the bottom m address bits. An "n-way set associative" cache with S sets has n cache locations in each set. Block b is mapped to set "b mod S" and may be stored in any of the n locations in that set with its upper address bits as a tag. To determine whether block b is in the cache, set "b mod S" is searched associatively for the tag.A direct mapped cache could be described as "one-way set associative", i.e. one location in each set whereas a fully associative cache is N-way associative (where N is the total number of blocks in the cache). Performance studies have shown that it is generally more effective to increase the number of entries rather than associativity and that 2- to 16-way set associative caches perform almost as well as fully associative caches at little extra cost over direct mapping.
source : http://encyclopedia2.thefreedictionary.com/set+associative+cache
source : http://encyclopedia2.thefreedictionary.com/set+associative+cache
Sunday, December 14, 2008
Have a blog, so make money from it
Every people who alway visit internet know about blog. Yes, a blog. Blog is a personal website that we can make without know about web programming. Thats the truth, a common user can make a blog so easy, just click and click then finish and you have create a blog. Blog is like online diary, most of user write down on their blog about their daily activities.
But does everyone know how to make money from that hobby, blogging?. Maybe there is a lot of blog user doesnt know about it. advertise on blogs are one of many way to monetize your blog. There is many way around internet, but this is the most used by blogger in common. For example, there are PTC ( pay to click ), PTR ( pay to review ) and many more.
Payingpost.com is one of the most popular program in review program. You just need to submit your blog, wait for reviewing by the payingpost.com crew, and make money with post a review that you can get. In payingpost.com we receive the payment with paypal transfer. It give a more reliable transfering money and it so secure. Many blogger have receive their payment and give testimonials that say payingpost.com is the best pay per review program in internet.
Payingpost.com has a good website looking,eye candy looking. Once you got there, you will know what you have to do. Sign up for new account is the first way for you. If you have any question, there is a crew that can answer all your question about this program with IM. They will be so pleasure to help you.
If you want to know more, read this article carefully. I suggest you that have a blog, you have to follow my way. Run your hobby, create money. Do you like it, right? I've join this payingpost.com for a long time, and I have a good income from it. I can work at home, enjoy my life, and I have money from my hobby.
Thursday, December 4, 2008
Technology And The Whistleblower
As the meeting comes to a close, your boss smirks with an self assured arrogance. He then says that you should seriously consider his offer, because he has it on good authority, that there may be a very localized downsizing in your department. Wouldn’t it be nice to smirk back and just say “no thanks”.
This scenario plays out more often then most people realize. With all of the recent business and government scandals there were a lot of people who knew that books were being cooked, laws being broken and the health of the public being put at risk, just to keep profits high and investors content. Many people felt that there was nothing they could do against powerful executives and corrupt bureaucrats. The credibility of a low level employee compared to that of a ‘successful’ corporate executive is a huge hurdle to overcome. Also, corporate lawyers are there to defend the company, even from internal hazards. So, once a person decides to speak up, they must be prepared to have their credibility brutally attacked and the onslaught of legal preceding from an all-star team of corporate lawyers.
Just the thought of legal proceedings can stop a person from making the ethical choice. It’s easy for people to be vilified by their employer, at which point the credibility of the person speaking out is destroyed. How is possible for a single person to fight a company or government with infinite resources? Many years ago, it was practically impossible. However, the “digital revolution” may have changed the balance of power. For a “whistleblower” to be effective they need proof of wrong doing and a method to communicate those issues to the public. The availability of compact electronic devices such as digital audio recorders and digital cameras allow an individual to document many of the issues and bring the power back to the whistleblower.
The first piece of technology that should be in every whistleblowers repertoire is a digital audio recorder. These devices are so small that they can be put in a shirt pocket without being noticed. Once you decide to “blow the whistle” you should start recording all of your conversations. Keep a log of the items discussed, so that you can refer to the appropriate recording when needed, otherwise you can spend hours going back over the content. The best part is that these devices are not expensive. A digital voice recorder costs about $100, or many times MP3 players have a microphone built into the device, so they can be used to record conversations.
Another device that is very handy is a voice modem with telephone recording software. This will allow you to, hook up your phone, and record any conversations that occur over the phone. If you get fired before you have all the evidence, sometimes telephone conversations, with the people in power, can help to document important facts, because people very rarely think they are being recorded and say things that they probably should not have.
Make sure you check your local laws regarding conversation recording. In most places it is legal to record with one-party consent. One-party consent means that if you are involved in the conversation, you do not need to notify the other parties that you are recording the conversation. In Canada, one-party consent is the law. In the United States it is a little more complicated, as some states have their own regulations. You can refer to this recording law chart (http://www.snakeoil.ca/docs/recordinglaw.html) to determine what laws affect you. If in doubt, speak with a lawyer.
The third device every whistleblower should have is a digital camera. Many times the violations are in manufacturing or packaging, which could be a public health concern. These can be very hard to document and prove, since the paper records may be manipulated. A picture says a thousand words though, and will help authorities uncover doctored documents. When taking pictures be very cautious as most companies prohibit camera’s on their premises. Many cell phones are now equipped with digital camera’s, so they are easier to conceal. Take as many pictures as you can and try to prove the date you took them. Some camera have a date stamp feature, even though this is easy to manipulate. The best option is to take a picture of the daily newspaper beside the offending subject. This is very hard for lawyers to argue against and disprove that the violations did occurred on that particular date.
The last piece of equipment needed is a computer. When the authorities begin investigating your complaint, you will need to produce your evidence such as documents pointing to the issues. Most corporations are moving towards a paperless environment, which means that these documents will only be accessible by a computer. The other important part your computer plays, is to backup all of those images and audio recordings. Make sure your computer has a CD writer or DVD writer. Take these backups and put them somewhere secure, like a bank deposit box.
One area of concern is the removal of corporate documents from the office. This can violate many legal agreements you may have signed. If you are worried about this, there is a very simple solution. Backup all of the evidence files at work and stash them somewhere in the office. In the ceiling or in duct work is a great place. Basically, anywhere nobody ever looks. When it is time to produce these documents, simply tell the authorities that you have stashed them in a safe place at the office. The evidence is kept safe and you haven’t violated any agreements, a win-win situation.
This scenario plays out more often then most people realize. With all of the recent business and government scandals there were a lot of people who knew that books were being cooked, laws being broken and the health of the public being put at risk, just to keep profits high and investors content. Many people felt that there was nothing they could do against powerful executives and corrupt bureaucrats. The credibility of a low level employee compared to that of a ‘successful’ corporate executive is a huge hurdle to overcome. Also, corporate lawyers are there to defend the company, even from internal hazards. So, once a person decides to speak up, they must be prepared to have their credibility brutally attacked and the onslaught of legal preceding from an all-star team of corporate lawyers.
Just the thought of legal proceedings can stop a person from making the ethical choice. It’s easy for people to be vilified by their employer, at which point the credibility of the person speaking out is destroyed. How is possible for a single person to fight a company or government with infinite resources? Many years ago, it was practically impossible. However, the “digital revolution” may have changed the balance of power. For a “whistleblower” to be effective they need proof of wrong doing and a method to communicate those issues to the public. The availability of compact electronic devices such as digital audio recorders and digital cameras allow an individual to document many of the issues and bring the power back to the whistleblower.
The first piece of technology that should be in every whistleblowers repertoire is a digital audio recorder. These devices are so small that they can be put in a shirt pocket without being noticed. Once you decide to “blow the whistle” you should start recording all of your conversations. Keep a log of the items discussed, so that you can refer to the appropriate recording when needed, otherwise you can spend hours going back over the content. The best part is that these devices are not expensive. A digital voice recorder costs about $100, or many times MP3 players have a microphone built into the device, so they can be used to record conversations.
Another device that is very handy is a voice modem with telephone recording software. This will allow you to, hook up your phone, and record any conversations that occur over the phone. If you get fired before you have all the evidence, sometimes telephone conversations, with the people in power, can help to document important facts, because people very rarely think they are being recorded and say things that they probably should not have.
Make sure you check your local laws regarding conversation recording. In most places it is legal to record with one-party consent. One-party consent means that if you are involved in the conversation, you do not need to notify the other parties that you are recording the conversation. In Canada, one-party consent is the law. In the United States it is a little more complicated, as some states have their own regulations. You can refer to this recording law chart (http://www.snakeoil.ca/docs/recordinglaw.html) to determine what laws affect you. If in doubt, speak with a lawyer.
The third device every whistleblower should have is a digital camera. Many times the violations are in manufacturing or packaging, which could be a public health concern. These can be very hard to document and prove, since the paper records may be manipulated. A picture says a thousand words though, and will help authorities uncover doctored documents. When taking pictures be very cautious as most companies prohibit camera’s on their premises. Many cell phones are now equipped with digital camera’s, so they are easier to conceal. Take as many pictures as you can and try to prove the date you took them. Some camera have a date stamp feature, even though this is easy to manipulate. The best option is to take a picture of the daily newspaper beside the offending subject. This is very hard for lawyers to argue against and disprove that the violations did occurred on that particular date.
The last piece of equipment needed is a computer. When the authorities begin investigating your complaint, you will need to produce your evidence such as documents pointing to the issues. Most corporations are moving towards a paperless environment, which means that these documents will only be accessible by a computer. The other important part your computer plays, is to backup all of those images and audio recordings. Make sure your computer has a CD writer or DVD writer. Take these backups and put them somewhere secure, like a bank deposit box.
One area of concern is the removal of corporate documents from the office. This can violate many legal agreements you may have signed. If you are worried about this, there is a very simple solution. Backup all of the evidence files at work and stash them somewhere in the office. In the ceiling or in duct work is a great place. Basically, anywhere nobody ever looks. When it is time to produce these documents, simply tell the authorities that you have stashed them in a safe place at the office. The evidence is kept safe and you haven’t violated any agreements, a win-win situation.
In the future, companies may begin banning digital devices from the workplace for the exact reasons being discussed here. However, if were are persistent, it may go the other way and corporate behaviour may change, which is the ultimate goal of being a whistleblower. The days of “plausible deniability” and “disgruntled employees” are disappearing quickly.
Writer : Darcy O'Neil
Source : http://www.articlecity.com/articles/computers_and_internet/article_1811.shtml
Wednesday, December 3, 2008
OpenOffice 3.0 Final
OpenOffice.org 3 is the leading open-source office software suite for word processing, spreadsheets, presentations, graphics, databases and more. It is available in many languages and works on all common computers. It stores all your data in an international open standard format and can also read and write files from other common office software packages. It can be downloaded and used completely free of charge for any purpose.
Great Software requires great people. OpenOffice.org 3 is the result of over twenty years' continuous high quality software engineering. Designed from the start as a single piece of software, OpenOffice.org 3 has a consistency and a quality that is world class. Its open-source development model means there are no secrets.
Roll your mouse over the screenshots for more details of the main components (requires javascript).
Easy to choose, easy to install, easy to learn - OpenOffice.org 3 is the easy choice for an office software suite. OpenOffice.org 3 is suitable for complete beginners, but if you have used any other office software, that's ok too. OpenOffice.org 3 will make full use of what you already know - through familiar screens and menus - and also what you have - by reading existing files with no retyping.
You may use OpenOffice.org 3 for any purpose without restriction: private, educational, public administration, commercial...
download link http://rapidshare.com/files/152437306/OOo_3.0.0_Win32Intel_install_en-US.exe
What is VPS??
A Virtual Private Server (VPS) is a hosting environment that combines the benefits of both shared hosting and dedicated hosting. It does this by creating a virtual server that runs inside a hardware server via a specially designed partition.
Each Virtual Private Server partition runs its own operating system in a secure and private environment and cannot be accessed or interrupted by its neighbours. This system gives you the same level of root access as a dedicated server whilst sharing the cost of the hardware. With a VPS you are virtually running your own server but at a fraction of the cost.
The flexibility of a dedicated server
Users share system resources, such as the CPU and memory, but unlike shared hosting (a virtual host on a shared hardware server ) the file system is fully partitioned. This means that up-time is more consistent; while root access to the server provides the flexibility to add and change modules and to install your own software.
As cost effective as shared hosting
Partitioning a single hardware server into multiple servers is nothing new. In fact, mainframe computers have long been partitioned into multiples. In 1996, Japanese giant Verio started to migrate the technique into hosting as a highly cost-effective storage solution.
How much technical knowledge do I need?
All our VPS options include the Plesk control panel, which makes it easier to administer your websites and services.
However, because a VPS gives you root-level access, allowing you to install whatever software you like, you will need some technical knowledge and understanding of how servers work to run a VPS effectively.
Why call it VPS 2.0?
We've called our new VPS range VPS 2.0 because of our next generation improvements to both performance and hardware. Our servers are 9th generation Dell machines with embedded Intel® Virtualization (VT®) optimisation in the Intel® boards. They are designed by Dell specifically to ramp up VPS performance.
The inclusion of the very latest range of software and control panels for Windows and Linux is accompanied by price reductions across the range so we're increasing performance, features and value at exactly the same time.
Powerful partnerships working for you
We've partnered with SWsoft to offer you a choice between Ubuntu Linux and Microsoft Windows virtual private server systems, making us the first UK host to deliver Windows SQL Server 2005 VPS hosting using the latest Plesk 8 and Virtuozzo Power Panel technology.
All VPS 2.0 systems are hosted on Dell PowerEdge 2950 servers with quad-core Intel® Xeon® processors for maximum multi-tasking performance and 15,000 RPM SCSI RAID 10 drives for data speed and integrity.
As we're a certified Intel Server Centre of Excellence using a Tier 1 Network with 50,000 Mbit Connectivity, you can also trust we set the access, speed and safety benchmarks you need.
Each Virtual Private Server partition runs its own operating system in a secure and private environment and cannot be accessed or interrupted by its neighbours. This system gives you the same level of root access as a dedicated server whilst sharing the cost of the hardware. With a VPS you are virtually running your own server but at a fraction of the cost.
The flexibility of a dedicated server
Users share system resources, such as the CPU and memory, but unlike shared hosting (a virtual host on a shared hardware server ) the file system is fully partitioned. This means that up-time is more consistent; while root access to the server provides the flexibility to add and change modules and to install your own software.
As cost effective as shared hosting
Partitioning a single hardware server into multiple servers is nothing new. In fact, mainframe computers have long been partitioned into multiples. In 1996, Japanese giant Verio started to migrate the technique into hosting as a highly cost-effective storage solution.
How much technical knowledge do I need?
All our VPS options include the Plesk control panel, which makes it easier to administer your websites and services.
However, because a VPS gives you root-level access, allowing you to install whatever software you like, you will need some technical knowledge and understanding of how servers work to run a VPS effectively.
Why call it VPS 2.0?
We've called our new VPS range VPS 2.0 because of our next generation improvements to both performance and hardware. Our servers are 9th generation Dell machines with embedded Intel® Virtualization (VT®) optimisation in the Intel® boards. They are designed by Dell specifically to ramp up VPS performance.
The inclusion of the very latest range of software and control panels for Windows and Linux is accompanied by price reductions across the range so we're increasing performance, features and value at exactly the same time.
Powerful partnerships working for you
We've partnered with SWsoft to offer you a choice between Ubuntu Linux and Microsoft Windows virtual private server systems, making us the first UK host to deliver Windows SQL Server 2005 VPS hosting using the latest Plesk 8 and Virtuozzo Power Panel technology.
All VPS 2.0 systems are hosted on Dell PowerEdge 2950 servers with quad-core Intel® Xeon® processors for maximum multi-tasking performance and 15,000 RPM SCSI RAID 10 drives for data speed and integrity.
As we're a certified Intel Server Centre of Excellence using a Tier 1 Network with 50,000 Mbit Connectivity, you can also trust we set the access, speed and safety benchmarks you need.
Tuesday, November 25, 2008
Carlsberg launches Web-TV
Who didnt know football?
www.partofthegame.tv
Almost every poeple in this world love this game. Oldman or youngman, man and women, has no different in this game. Maybe you loose your football club match? Don't worry about that, you can find it in Partofthegame.tv. Partofthegame.tv is one from a lot of web tv that give you what you want.
Carlsberg web-tv has so much galery of various match around the world. Find and search what you want to see, especialy football moment.
Be sure not to miss the video clips about football funnies and rituals from the Football Magic.
Carlsberg web-tv has so much galery of various match around the world. Find and search what you want to see, especialy football moment.
Be sure not to miss the video clips about football funnies and rituals from the Football Magic.
Sunday, November 23, 2008
Routing Versus Bridging
When Connecting to the Wireless, xDSL or Cable Network
Summary:
As wireless, cable and xDSL technologies emerge, a growing consideration is how to connect to the network. Although much can be said about different methods, it really boils down to two: bridging or routing. Now for those experienced in networking, they will know that this question has been around since routing and bridging technologies have been. However the new element here is that the discussions always centered on LAN’s and/or private WAN’s. When connecting to the Internet there are new considerations to keep in mind when making your decision. This technical document is geared for those who need assistance in the decision for choosing what equipment and how to connect to the cable or xDSL network.
Background:
Now before we can argue routing versus bridging (or vice versa for that matter) we need to be clear on what both devices are and how they behave. So let’s define each one:
Bridge:
A bridge is a device that connects two segments of the same network. The two networks being connected can be alike or dissimilar. Unlike routers, bridges are protocol-independent. They simply forward packets without analyzing and re-routing messages.
Router:
A router is a device that connects two distinct networks. Routers are similar to bridges, but provide additional functionality, such as the ability to filter messages and forward them to different places based on various criteria. The Internet uses routers extensively to forward packets from one host to another.
Based on these definitions we can see that key difference between a bridge and router is that a bridge does not look at protocols and a router does. A bridge does not look at traffic for the purpose of allowing or disallowing it, and it does not decide what to do with certain types of traffic; it simply moves data from one network to another. Whereas a router examines protocols and decides what to do with each packet based on defined criteria.
Router vs. Bridge in Cable & DSL Environments
When you order Internet access either via a cable or xDSL connection, they will offer you a bridge (although it may often be called a “modem,” it is a bridge). These are very low cost (usually around $200,) and will connect your machine to the ISP’s network. Now this is a cost-effective solution, however there are some very apparent reasons on why you should consider a router over a bridge. Let’s look at an example to illustrate this point
Security Risk: In this example, we have two different customers bridged to the Internet using the same ISP. You can see that both customers have IP addresses on the same IP network. This means that broadcast from Customer A’s network will propagate to Customer’s B network. For example if machines on both networks are utilizing file and print services through the Windows Network, it is perfectly plausible (and has happened) that machines from Customer A can show up in the Network Neighborhood of Machines on Customer B’s network. Now for security reasons alone this is a very undesirable situation.
Everyone is talking about firewalls, filtering, etc. Many people connecting to the Internet today do not realize how vulnerable they are to attacks from the Internet. When utilizing a dial up connection, the exposure is only for the time you are connected, however, along with the all the benefits of a permanent connection, there is a big drawback: your network is exposed to the Internet 24 hours a day, 7 days a week. When you are at home asleep, it could be quite possible someone out there is working away at your network in the hopes of destroying or stealing data. Although this is not a pleasant thought there are very simple means to prevent this happening.
The first thing is have a routed account. With a routed account you have a device examining all traffic before it enters your network. This means that traffic not destined for your network will not be routed to your LAN, broadcast storms, and other network related issues on other networks connecting to your ISP will not effect your network. Now the biggest gain from a routed account is security. A Router has the ability to filter Internet traffic. This means the router connecting you to the Internet can discriminate which traffic it will allow into your network, and which traffic it will not. A Router also has the ability to “hide” all of the IP addresses on your network and make them appear as if the were only one IP address out on the Internet. By doing this, you have just eliminated 90% of all security threats.
Other Benefits: Aside from security other benefits of using a Router over a bridge include:
· You will have a contiguous block of IP addresses, rather than sporadic address across a network.
· A Router can use DHCP to assign workstations addresses on the LAN, preventing specific configuration in each device.
· A router has the ability to use NAT (Network Address Translation), thus only requiring you to obtain 1 IP address from your ISP. Cost saving as well as security enhancement
For the above reasons it seems quite clear that a routed account has distinct advantages over a bridged connection. For wireless bridge connections an Ethernet broadband router can be placed between the bridge and the LAN, thus providing all the benefits of routing to cable, ADSL and other environments.
Wednesday, May 28, 2008
What is the purpose of Wi-Fi ad-hoc mode? Why would I use it?
The 802.11 standard defines two modes of operation: Infrastructure mode, where all stations communicate through an access point, and ad-hoc mode, where stations communicate directly without the help of an intermediary. Ad-hoc mode can be useful for temporary peer-to-peer applications, such as when two laptop users want to exchange files over Wi-Fi.
Most businesses discourage use of ad-hoc mode because they prefer to enforce corporate security policy at the access point and gateway or switch connected to the access point. Users that communicate directly over ad-hoc mode essentially bypass those security measures. Ad-hoc mode can even be used as an attack method. For example, a Windows XP PC that previously associated to an access point with a given name (SSID) can be tricked into automatically re-associating in Ad-hoc mode to an attacker's laptop that advertises that SSID. You avoid this attack by configuring XP (or any other wireless client software) to associate to preferred SSIDs in infrastructure mode only.
On the other hand, several vendors are now using ad-hoc mode as the foundation for building wireless mesh networks. Mesh networks have many applications, including outdoor metropolitan networks and mobile ad-hoc networks (MANETs). To learn more about Ad-hoc mode and its use in mesh networks, visit this NIST resource page. A standard for mesh networks is now under development, designated IEEE 802.11s.
In short, ad-hoc mode has many constructive uses, but unless you have a specific reason for enabling, your safest best today is to disable ad-hoc mode to prevent unwanted or risky associations.
source
What is Hub
In general, a hub is the central part of a wheel where the spokes come together. The term is familiar to frequent fliers who travel through airport "hubs" to make connecting flights from one point to another. In data communications, a hub is a place of convergence where data arrives from one or more directions and is forwarded out in one or more other directions. A hub usually includes a switch of some kind. (And a product that is called a "switch" could usually be considered a hub as well.) The distinction seems to be that the hub is the place where data comes together and the switch is what determines how and where data is forwarded from the place where data comes together. Regarded in its switching aspects, a hub can also include a router.
1) In describing network topologies, a hub
2) As a network product, a hub may include a group of modem cards for dial-in users, a gateway card for connections to a local area network (for example, an Ethernet or a Token Ring), and a connection to a
What is bridge in network world
In telecommunication networks, a bridge is a product that connects a local area network (LAN) to another local area network that uses the same protocol (for example, Ethernet or Token Ring). You can envision a bridge as being a device that decides whether a message from you to someone else is going to the local area network in your building or to someone on the local area network in the building across the street. A bridge examines each message on a LAN, "passing" those known to be within the same LAN, and forwarding those known to be on the other interconnected LAN (or LANs).
source
In bridging networks, computer or node addresses have no specific relationship to location. For this reason, messages are sent out to every address on the network and accepted only by the intended destination node. Bridges learn which addresses are on which network and develop a learning table so that subsequent messages can be forwarded to the right network.
Bridging networks are generally always interconnected local area networks since broadcasting every message to all possible destinations would flood a larger network with unnecessary traffic. For this reason, router networks such as the Internet use a scheme that assigns addresses to nodes so that a message or packet can be forwarded only in one general direction rather than forwarded in all directions.
A bridge works at the data-link (physical network) level of a network, copying a data frame from one network to the next network along the communications path.
A bridge is sometimes combined with a router in a product called a brouter.
source
Tuesday, May 27, 2008
Switch is .....
In a telecommunications network, a switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination. In the traditional circuit-switched telephone network, one or more switches are used to set up a dedicated though temporary connection or circuit for an exchange between two or more parties. On an Ethernet local area network (LAN), a switch determines from the physical device (
In the Open Systems Interconnection (OSI) communications model, a switch performs the layer 2 or Data-Link layer function. That is, it simply looks at each packet or data unit and determines from a physical address (the "MAC address") which device a data unit is intended for and switches it out toward that device. However, in wide area networks such as the Internet, the destination address requires a look-up in a routing table by a device known as a router. Some newer switches also perform routing functions (layer 3 or the Network layer functions in OSI) and are sometimes called
On larger networks, the trip from one switch point to another in the network is called a hop. The time a switch takes to figure out where to forward a data unit is called its latency. The price paid for having the flexibility that switches provide in a network is this latency. Switches are found at the backbone and gateway levels of a network where one network connects with another and at the subnetwork level where data is being forwarded close to its destination or origin. The former are often known as core switches and the latter as desktop switches.
In the simplest networks, a switch is not required for messages that are sent and received within the network. For example, a local area network may be organized in a Token Ring or bus arrangement in which each possible destination inspects each message and reads any message with its address.
Circuit-Switching version Packet-Switching
A network's paths can be used exclusively for a certain duration by two or more parties and then switched for use to another set of parties. This type of "switching" is known as circuit-switching and is really a dedicated and continuously connected path for its duration. Today, an ordinary voice phone call generally uses circuit-switching. Most data today is sent, using digital signals, over networks that use packet-switching. Using packet-switching, all network users can share the same paths at the same time and the particular route a data unit travels can be varied as conditions change. In packet-switching, a message is divided into packets, which are units of a certain number of bytes. The network addresses of the sender and of the destination are added to the packet. Each network point looks at the packet to see where to send it next. Packets in the same message may travel different routes and may not arrive in the same order that they were sent. At the destination, the packets in a message are collected and reassembled into the original message.
Router is ......
In packet-switched networks such as the Internet, a router is a device or, in some cases, software in a computer, that determines the next network point to which a packet should be forwarded toward its destination. The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to. A router is located at any gateway (where one network meets another), including each point-of-presence on the Internet. A router is often included as part of a network switch.
A router may create or maintain a table of the available routes and their conditions and use this information along with distance and cost algorithms to determine the best route for a given packet. Typically, a packet may travel through a number of network points with routers before arriving at its destination. Routing is a function associated with the Network layer (layer 3) in the standard model of network programming, the Open Systems Interconnection (OSI) model. A
An edge router is a router that interfaces with an asynchronous transfer mode (ATM) network. A brouter is a network bridge combined with a router.
For home and business computer users who have high-speed Internet connections such as cable, satellite, or DSL, a router can act as a hardware firewall. This is true even if the home or business has only one computer. Many engineers believe that the use of a router provides better protection against hacking than a software firewall, because no computer
Thursday, April 10, 2008
RAM Overview
by : Christophe Catesson
There are two big categories of random access memories:
* Dynamic memories (DRAM, Dynamic Random Access Module), not very costly. They are in most cases used for the central memory of the computer
* Static memories (SRAM, Static Random Access Module), quick and expensive. SRAM is notably used for cache memories of the processor
Functioning of the random access memory
The random access memory is constituted of hundred of thousand small condensers storing charges. When it is loaded, the logical state of the condenser is equal to 1, otherwise it belongs to 0, what means that every condenser represents one bit of memory.
Given that condensers off-load, it is always necessary to recharge them in a space of regular time called cycle of refreshment. Memory DRAM requires cycles of refreshment for instance (Ns) is about 15 nanoseconds.
Every condenser is coupled with a transistor allowing to "recover « or to change the state of the condenser. These transistors are lined up in form of matrix, that is they achieve a hut memory (so called memory) by a line and a column.
So, for a memory of type DRAM, the time of access is of 60 nanoseconds (35ns of delay of cycle and 25 ns of time of latency). On a computer, the time of cycle corresponds contrary to the frequency of the clock, for instance for a computer pulsated in 200 MHz, the time of cycle is 5 ns (1 / (200*106)).
As a result a computer having a frequency well brought up and using memories the time of access of which is much longer than the time of cycle of the processor must perform cycles of wait to access to the memory. In the case of a computer pulsated in 200 MHz using memories of types DRAM (which the time of access is of 60ns), there are 11 cycles of wait as a cycle of transfer. The performances of the computer are of as much diminished as there are cycles
Formats of Random Access Memory (RAM)
There are numerous types of random access memories. These all come in the form of barrettes of memory attachable on the motherboard.
* SIMM (Single Inline Memory Module): it is about printed circuits among which one of the faces has fleas of memory. There are two types of barrettes SIMM, according to the number of connector cables (30 or 72)
* DIMM (Dual Inline Memory Modulates) are from memories 64 bits, what explains why it is not necessary to match them. Barrettes DIMM have fleas of memory on both sides of printed circuit and have also 84 connector cables on each side, what endows them with a total of 168 brooches. They have bigger dimensions than barrettes SIMM (130x25mm).
* RIMM (Rambus Inline Memory Module, conscripts also RD-RAM or DRD-RAM) are from memories 64 bits developed by the society Rambus. They have 184 brooches. These barrettes have two notches of location (détrompeurs), avoiding very risk of confusion with the previous modules. Considering their well brought up speed of transfer, barrettes RIMM have a thermal film made responsible for ameliorating the clearing up of warmth. As in the case of DIMM, there are modules of smaller size, called SO RIMM (Small Outline RIMM), intended for laptop computers. Barrettes SO RIMM include only 160 brooches.
* DRAM (Dynamic RAM, dynamic RAM) is the type of memo most spread at the beginning of the millennium. It is about a memory from which transistors are lined up in a matrix according to lines and of columns. A transistor, coupled with a condenser gives the information of a bit. 1 byte consisting of 8 bits, a barrette of memory 256 Mb DRAM will contain 256 therefore * 2^10 * 2^10 = 256 * on 1024 * on 1024 = 268 435 456 bytes = 268 435 456 * 8 = 2 147 483 648 bits = 2 147 483 648 transistors. A 256 Mb barrette has so in reality a capacity of 268 435 456 bytes, that is 268 Mb! These are memories from which the time of access is 60 ns. On the other hand, accesses memory are made in general on data lined up consecutively in memory. So the mode of access in gust (burst mode) allows to achieve the three successive data in the first one without time of additional latency.
* DRAM FPM to speed up accesses to DRAM, there is a technology, called pagination consisting in achieving data located on the same column by changing the address of the line only, what allows to avoid the repetition of the number of column between the reading of each of the lines. They speak then about DRAM FPM (Fast Page Mode). FPM allows to acquire time of access in the order of 70 - 80 nanoseconds for a frequency of functioning that can go from 25 to 33 Mhz.
* DRAM EDO (Extended Data Out, Goes out of data ameliorated sometimes also called "hyper-page") appears in 1995. The technology used with this type of memory consists in addressing the following column during the reading of the data of a column. It creates an overlapping of accesses allowing to save time on every cycle. The time of access to memory EDO is therefore about 50 - 60 nanoseconds for a frequency of functioning going 33 - 66 Mhz. So, RAM EDO, when it is used in mode gust allows to acquire cycles of form 5-2-2-2, that is a benefit of 4 cycles on the access to 4 data. As much as memory EDO did not accept the upper frequencies in 66 Mhz, it disappeared in aid of SDRAM.
* SDRAM (Synchronous DRAM, translate synchronous RAM), appeared in 1997, allows a reading of data synchronized with the bus of the card-mother, contrary to memories EDO and FPM (qualified as asynchronous) having their own clock. SDRAM allows therefore to free itself from time of wait owed to synchronization with the card-mother. This one allows to acquire a cycle in mode gust of form 5-1-1-1, that is to say benefit of 3 cycles in comparison with RAM EDO. In that way SDRAM is able of working with a cadenza going until 150 Mhz, allowing him to acquire from time of access about 10 ns.
* DR-SDRAM (Direct Rambus DRAM or else RDRAM) is a type of memory allowing to transfer data on a bus of 16 wide bits to a cadenza of 800Mhz, what confers on him a band passer-by of 1,6 Go / s. As SDRAM, this type of memory is synchronized with the clock of the bus to ameliorate exchanges of data.
* DDR-SDRAM (Double Dated Miss SDRAM) is a memory based on technology SDRAM, allowing to double the rate of transfer of SDRAM with equal frequency. Reading or writing of data in memory am accomplished on the basis of a clock. Standard memory DRAM uses a method conscript SDR (Single Data Fails) consisting in reading or writing data in every forehead going up. DDR allows to double the frequency of reading / writings, with a clock pulsated in the same frequency, by sending data in every forehead going up, as well as in every downward forehead. Memory DDR has in general a commercial appellation of type PCXXXX where "XXXX " represent the debit side in Mb / s.
* DDR2 (or DDR-II) allows to attain twice as well brought up debit sides as DDR with equal external frequency. They speak about QDR (Quadruple Dated Fail or quad-pumped) to indicate the method of reading and used writing. Memory DDR2 uses in effect two channels separated for reading and for writing, so it is able of sending or of accepting twice more data than DDR.
source
There are two big categories of random access memories:
* Dynamic memories (DRAM, Dynamic Random Access Module), not very costly. They are in most cases used for the central memory of the computer
* Static memories (SRAM, Static Random Access Module), quick and expensive. SRAM is notably used for cache memories of the processor
Functioning of the random access memory
The random access memory is constituted of hundred of thousand small condensers storing charges. When it is loaded, the logical state of the condenser is equal to 1, otherwise it belongs to 0, what means that every condenser represents one bit of memory.
Given that condensers off-load, it is always necessary to recharge them in a space of regular time called cycle of refreshment. Memory DRAM requires cycles of refreshment for instance (Ns) is about 15 nanoseconds.
Every condenser is coupled with a transistor allowing to "recover « or to change the state of the condenser. These transistors are lined up in form of matrix, that is they achieve a hut memory (so called memory) by a line and a column.
So, for a memory of type DRAM, the time of access is of 60 nanoseconds (35ns of delay of cycle and 25 ns of time of latency). On a computer, the time of cycle corresponds contrary to the frequency of the clock, for instance for a computer pulsated in 200 MHz, the time of cycle is 5 ns (1 / (200*106)).
As a result a computer having a frequency well brought up and using memories the time of access of which is much longer than the time of cycle of the processor must perform cycles of wait to access to the memory. In the case of a computer pulsated in 200 MHz using memories of types DRAM (which the time of access is of 60ns), there are 11 cycles of wait as a cycle of transfer. The performances of the computer are of as much diminished as there are cycles
Formats of Random Access Memory (RAM)
There are numerous types of random access memories. These all come in the form of barrettes of memory attachable on the motherboard.
* SIMM (Single Inline Memory Module): it is about printed circuits among which one of the faces has fleas of memory. There are two types of barrettes SIMM, according to the number of connector cables (30 or 72)
* DIMM (Dual Inline Memory Modulates) are from memories 64 bits, what explains why it is not necessary to match them. Barrettes DIMM have fleas of memory on both sides of printed circuit and have also 84 connector cables on each side, what endows them with a total of 168 brooches. They have bigger dimensions than barrettes SIMM (130x25mm).
* RIMM (Rambus Inline Memory Module, conscripts also RD-RAM or DRD-RAM) are from memories 64 bits developed by the society Rambus. They have 184 brooches. These barrettes have two notches of location (détrompeurs), avoiding very risk of confusion with the previous modules. Considering their well brought up speed of transfer, barrettes RIMM have a thermal film made responsible for ameliorating the clearing up of warmth. As in the case of DIMM, there are modules of smaller size, called SO RIMM (Small Outline RIMM), intended for laptop computers. Barrettes SO RIMM include only 160 brooches.
* DRAM (Dynamic RAM, dynamic RAM) is the type of memo most spread at the beginning of the millennium. It is about a memory from which transistors are lined up in a matrix according to lines and of columns. A transistor, coupled with a condenser gives the information of a bit. 1 byte consisting of 8 bits, a barrette of memory 256 Mb DRAM will contain 256 therefore * 2^10 * 2^10 = 256 * on 1024 * on 1024 = 268 435 456 bytes = 268 435 456 * 8 = 2 147 483 648 bits = 2 147 483 648 transistors. A 256 Mb barrette has so in reality a capacity of 268 435 456 bytes, that is 268 Mb! These are memories from which the time of access is 60 ns. On the other hand, accesses memory are made in general on data lined up consecutively in memory. So the mode of access in gust (burst mode) allows to achieve the three successive data in the first one without time of additional latency.
* DRAM FPM to speed up accesses to DRAM, there is a technology, called pagination consisting in achieving data located on the same column by changing the address of the line only, what allows to avoid the repetition of the number of column between the reading of each of the lines. They speak then about DRAM FPM (Fast Page Mode). FPM allows to acquire time of access in the order of 70 - 80 nanoseconds for a frequency of functioning that can go from 25 to 33 Mhz.
* DRAM EDO (Extended Data Out, Goes out of data ameliorated sometimes also called "hyper-page") appears in 1995. The technology used with this type of memory consists in addressing the following column during the reading of the data of a column. It creates an overlapping of accesses allowing to save time on every cycle. The time of access to memory EDO is therefore about 50 - 60 nanoseconds for a frequency of functioning going 33 - 66 Mhz. So, RAM EDO, when it is used in mode gust allows to acquire cycles of form 5-2-2-2, that is a benefit of 4 cycles on the access to 4 data. As much as memory EDO did not accept the upper frequencies in 66 Mhz, it disappeared in aid of SDRAM.
* SDRAM (Synchronous DRAM, translate synchronous RAM), appeared in 1997, allows a reading of data synchronized with the bus of the card-mother, contrary to memories EDO and FPM (qualified as asynchronous) having their own clock. SDRAM allows therefore to free itself from time of wait owed to synchronization with the card-mother. This one allows to acquire a cycle in mode gust of form 5-1-1-1, that is to say benefit of 3 cycles in comparison with RAM EDO. In that way SDRAM is able of working with a cadenza going until 150 Mhz, allowing him to acquire from time of access about 10 ns.
* DR-SDRAM (Direct Rambus DRAM or else RDRAM) is a type of memory allowing to transfer data on a bus of 16 wide bits to a cadenza of 800Mhz, what confers on him a band passer-by of 1,6 Go / s. As SDRAM, this type of memory is synchronized with the clock of the bus to ameliorate exchanges of data.
* DDR-SDRAM (Double Dated Miss SDRAM) is a memory based on technology SDRAM, allowing to double the rate of transfer of SDRAM with equal frequency. Reading or writing of data in memory am accomplished on the basis of a clock. Standard memory DRAM uses a method conscript SDR (Single Data Fails) consisting in reading or writing data in every forehead going up. DDR allows to double the frequency of reading / writings, with a clock pulsated in the same frequency, by sending data in every forehead going up, as well as in every downward forehead. Memory DDR has in general a commercial appellation of type PCXXXX where "XXXX " represent the debit side in Mb / s.
* DDR2 (or DDR-II) allows to attain twice as well brought up debit sides as DDR with equal external frequency. They speak about QDR (Quadruple Dated Fail or quad-pumped) to indicate the method of reading and used writing. Memory DDR2 uses in effect two channels separated for reading and for writing, so it is able of sending or of accepting twice more data than DDR.
source
Wednesday, April 2, 2008
Microsoft Server 2008 Certification: Routing's Not Just For Cisco Exams Anymore!
by: Chris Bryant
Knowing routing theory and routing protocols has always been a big part of earning your CCNA and CCNP certifications. According to Microsoft's exam blueprints for the Server 2008 certification exams, that knowledge will also serve you well on your Microsoft exams.
The topic outline for the Configuring Windows Server 2008 Network Infrastructure exam (70-642) specifically mentions routing and routing protocols as exam topics. Specifically mentioned are RIP, OSPF, and static routing - three topics every CCNA and CCNP candidate will be well prepared to handle!
IPSec isn't part of the CCNA exam, but you'll see it on at least one CCNP exam, and it's also listed as a 70-642 exam topic. IPv6 and IPv4 addressing are both covered on the 70-642 as well.
Microsoft's website lists the following major skills you should expect to see on this exam:
Configuring IP addresses and Services (routing with RIP and OSPF, static routing, persistent routing, addressing, DHCP and DHCP options including relay agents, IPSec policies, Authentication Header and Encapsulating Security Payload, subnetting, supernetting)
Configuring Name Resolution (DNS configuration, zones, records, replication, and integration with Active Directory, and client computer name resolution techniques)
Configuring Network Access (includes NAT, VPNs, RADIUS, 802.1x authentication, MS-CHAP, firewalls, and remote authentication)
Configuring File And Print Services (self-explanatory)
Monitoring And Managing A Network Infrastructure (includes SNMP and Windows Server Update Services)
Your CCNA and CCNP preparation will not quite be enough to get you past this exam, but as you can see, it'll give you a great head start!
source:
Knowing routing theory and routing protocols has always been a big part of earning your CCNA and CCNP certifications. According to Microsoft's exam blueprints for the Server 2008 certification exams, that knowledge will also serve you well on your Microsoft exams.
The topic outline for the Configuring Windows Server 2008 Network Infrastructure exam (70-642) specifically mentions routing and routing protocols as exam topics. Specifically mentioned are RIP, OSPF, and static routing - three topics every CCNA and CCNP candidate will be well prepared to handle!
IPSec isn't part of the CCNA exam, but you'll see it on at least one CCNP exam, and it's also listed as a 70-642 exam topic. IPv6 and IPv4 addressing are both covered on the 70-642 as well.
Microsoft's website lists the following major skills you should expect to see on this exam:
Configuring IP addresses and Services (routing with RIP and OSPF, static routing, persistent routing, addressing, DHCP and DHCP options including relay agents, IPSec policies, Authentication Header and Encapsulating Security Payload, subnetting, supernetting)
Configuring Name Resolution (DNS configuration, zones, records, replication, and integration with Active Directory, and client computer name resolution techniques)
Configuring Network Access (includes NAT, VPNs, RADIUS, 802.1x authentication, MS-CHAP, firewalls, and remote authentication)
Configuring File And Print Services (self-explanatory)
Monitoring And Managing A Network Infrastructure (includes SNMP and Windows Server Update Services)
Your CCNA and CCNP preparation will not quite be enough to get you past this exam, but as you can see, it'll give you a great head start!
source:
Monday, March 24, 2008
What's WiMAX?
WiMAX is a short name for Worldwide Interoperability of Microwave Access. WiMAX is described in IEEE 802.16 Wireless Metropolitan Area Network (MAN) standard. It is expected that WiMAX compliant systems will provide fixed wireless alternative to conventional DSL and Cable Internet.
Typically, a WiMAX system consists of two parts:
- A WiMAX Base Station: Base station consists of indoor electronics and a WiMAX tower. Typically, a base station can cover up to 10 km radius (Theoretically, a base station can cover up to 50 kilo meter radius or 30 miles, however practical considerations limit it to about 10 km or 6 miles). Any wireless node within the coverage area would be able to access the Internet.
- A WiMAX receiver - The receiver and antenna could be a stand-alone box or a PCMCIA card that sits in your laptop or computer. Access to WiMAX base station is similar to accessing a Wireless Access Point in a WiFi network, but the coverage is more.
Several base stations can be connected with one another by use of high-speed backhaul microwave links. This would allow for roaming by a WiMAX subscriber from one base station to another base station area, similar to roaming enabled by Cellular phone companies.
Important Wireless MAN IEEE 802.16 (WiMAX) Specifications
Range - 30-mile (50-km) radius from base station
Speed - Up to 70 megabits per second
Non-Line-of-sight (NLoS) between user and base station
Frequency bands - 2 to 11 GHz and 10 to 66 GHz (licensed and unlicensed bands)
Defines both the MAC and PHY layers and allows multiple PHY-layer specifications.
Thursday, December 27, 2007
Why It’s Crucial To Have A Dedicated Server
by: Stu Pearson
A dedicated server is a single web server or computer on the internet that hosts websites and shows pages as viewers request. A dedicated server is within a network of computers, exclusively dedicated to one costumer or a large business, since it can meet many needs.
Dedicated servers are most commonly used in the web hosting industry; hundreds of sites are hosted under one dedicated server. A dedicated server is considered to be the next step on from shared hosting environments. Having your own dedicated server makes you free of worry about other websites slowing you down or crashing your server. Dedicated servers also give you total control, and allows for installing software on your website that opens doors for gaining extra performance.
The advantage of having a dedicated server is that the clients of the server can customize both hardware and software setup so they meet needs like faster data access and effortless accommodation of traffic on the site.
These dedicated servers come with good costumer service. The web host works with the client in making sure that the dedicated server meets the needs of the client. In cases of companies having several divisions like a chain of outlets, it is still crucial for each to have their own dedicated server because they can create many domains on a single server easily, which results in more efficiency rather than having to lease host space on different web servers for each division or outlet individually.
For large companies having websites for every dealership such as motorcycle manufacturers, the advantage of having a dedicated server is that the parent company can put all of the websites for each dealership under the same server.
Here’s how it works. Assume a company named “Taurus Cars Corp.” is running a series of dealerships, the parent company could host an individual website for every dealership. Each website may look like this; for the parent company “www.taurusmotorscorp.com”, for the dealership in Florida “www.taurusmotorsflorida.com “, for the dealership in Colorado “www.taurusmotorscolorado.com” and so on.
The advantage of this setup is the dealership in Florida is using the same online tools as the dealership in Colorado. Making the online presence of the company Taurus Motors Corp. very streamlined and cost-efficient, while making things significantly easier for the company’s administration and support, also known as customization and uniform of point of sale software. Considering the websites of each of the different divisions or dealerships residing on one dedicated server, makes this advantage beneficial in terms of increasing sales.
In some cases other business want to use dedicated servers for the sole purpose of customization, costumer service, and fast access. They host websites themselves or better yet sub-lease the extra space for interested companies to set up their websites and domains. The advantage derived by any business under a dedicated server is the ability to enhance security.
All these advantages imply that dedicated servers are the best option for most large companies or businesses. Hosting personal websites or small business websites in general doesn’t require a dedicated server, instead for this purpose you can lease from a standard web host.
source : articlecity
A dedicated server is a single web server or computer on the internet that hosts websites and shows pages as viewers request. A dedicated server is within a network of computers, exclusively dedicated to one costumer or a large business, since it can meet many needs.
Dedicated servers are most commonly used in the web hosting industry; hundreds of sites are hosted under one dedicated server. A dedicated server is considered to be the next step on from shared hosting environments. Having your own dedicated server makes you free of worry about other websites slowing you down or crashing your server. Dedicated servers also give you total control, and allows for installing software on your website that opens doors for gaining extra performance.
The advantage of having a dedicated server is that the clients of the server can customize both hardware and software setup so they meet needs like faster data access and effortless accommodation of traffic on the site.
These dedicated servers come with good costumer service. The web host works with the client in making sure that the dedicated server meets the needs of the client. In cases of companies having several divisions like a chain of outlets, it is still crucial for each to have their own dedicated server because they can create many domains on a single server easily, which results in more efficiency rather than having to lease host space on different web servers for each division or outlet individually.
For large companies having websites for every dealership such as motorcycle manufacturers, the advantage of having a dedicated server is that the parent company can put all of the websites for each dealership under the same server.
Here’s how it works. Assume a company named “Taurus Cars Corp.” is running a series of dealerships, the parent company could host an individual website for every dealership. Each website may look like this; for the parent company “www.taurusmotorscorp.com”, for the dealership in Florida “www.taurusmotorsflorida.com “, for the dealership in Colorado “www.taurusmotorscolorado.com” and so on.
The advantage of this setup is the dealership in Florida is using the same online tools as the dealership in Colorado. Making the online presence of the company Taurus Motors Corp. very streamlined and cost-efficient, while making things significantly easier for the company’s administration and support, also known as customization and uniform of point of sale software. Considering the websites of each of the different divisions or dealerships residing on one dedicated server, makes this advantage beneficial in terms of increasing sales.
In some cases other business want to use dedicated servers for the sole purpose of customization, costumer service, and fast access. They host websites themselves or better yet sub-lease the extra space for interested companies to set up their websites and domains. The advantage derived by any business under a dedicated server is the ability to enhance security.
All these advantages imply that dedicated servers are the best option for most large companies or businesses. Hosting personal websites or small business websites in general doesn’t require a dedicated server, instead for this purpose you can lease from a standard web host.
source : articlecity
NetSuite IPO generates $185 million
NetSuite's initial public offering raised $185.4 million, close to double the amount the company originally forecast the IPO would generate and a positive sign for the market of hosted, software-as-a-service business applications.
NetSuite, a provider of hosted applications for small and midsize organizations, sold 6.2 million shares of common stock at $26 per share via auction and its underwriters acted on their option to buy an additional 930,000 shares, the company said Wednesday.
The $185.4 million is a gross amount from which underwriting discounts and expenses will be deducted, the company said. Moreover, 365,000 of the shares bought by the underwriters were owned by stockholders like NetSuite's CEO and chief technology officer, so the proceeds from those shares -- about $9.5 million -- won't go to the company.
In the final IPO prospectus, NetSuite had estimated that, if the underwriters exercised their option in full -- as they did -- NetSuite's IPO net proceeds would be approximately $161.9 million.
NetSuite initially set a range of $13 to $16 per share for its IPO but subsequently raised it and eventually set the price at $26 per share on Thursday of last week, the day when the stock started trading on the New York Stock Exchange under the "N" symbol.
At midmorning Wednesday, the stock was trading at $34.85, down about 10 percent from its previous close. Its highest point so far is $45.98.
Incorporated in 1998, NetSuite sells ERP (enterprise resource planning), CRM (customer relationship management) and e-commerce applications on a hosted, subscription-based model, in which customers access the software via the Internet and don't need to install it on their premises.
This software-as-a-service model, championed by companies like Salesforce.com and Google, is considered a significant threat to the traditional approach from vendors like Microsoft of having customers implement software on their own PCs and servers.
As of Sept. 30 of this year, NetSuite had over 5,400 active customers, according to its IPO prospectus . In 2006, the company had revenue of $67.2 million and a net loss of $35.7 million. In the first nine months of this year, it generated $76.8 million in revenue and racked up a net loss of $20.6 million, according to the prospectus.
NetSuite plans to use its IPO proceeds to pay off an $8 million balance on a line of credit with Tako Ventures, an entity controlled by Oracle CEO Larry Ellison, and to possibly make acquisitions.
As of Nov. 30, Ellison controlled about 60 percent of NetSuite's outstanding stock -- some 31.9 million shares -- but Ellison transferred those shares into a holding company, NetSuite Restricted Holdings. The move is meant to "effectively eliminate" Ellison's voting power and avoid potential conflicts of interests, according to the prospectus.
NetSuite also plans to devote between $10 million and $15 million for capital expenditures, including the purchase of property, plant and equipment and the addition of a second data-center facility, and for working capital and other general purposes, including its international expansion. NetSuite currently provides its hosted applications out of a single data center, which the company admits in the prospectus is a risk that could harm its business should there be any service disruption at this facility.
NetSuite also said it may use a portion of the net proceeds to acquire other businesses, products or technologies, although it doesn't have any agreements or commitments for any specific acquisitions at the moment. The money it doesn't spend will be invested in short-term, interest-bearing investment grade securities.
NetSuite, a provider of hosted applications for small and midsize organizations, sold 6.2 million shares of common stock at $26 per share via auction and its underwriters acted on their option to buy an additional 930,000 shares, the company said Wednesday.
The $185.4 million is a gross amount from which underwriting discounts and expenses will be deducted, the company said. Moreover, 365,000 of the shares bought by the underwriters were owned by stockholders like NetSuite's CEO and chief technology officer, so the proceeds from those shares -- about $9.5 million -- won't go to the company.
In the final IPO prospectus, NetSuite had estimated that, if the underwriters exercised their option in full -- as they did -- NetSuite's IPO net proceeds would be approximately $161.9 million.
NetSuite initially set a range of $13 to $16 per share for its IPO but subsequently raised it and eventually set the price at $26 per share on Thursday of last week, the day when the stock started trading on the New York Stock Exchange under the "N" symbol.
At midmorning Wednesday, the stock was trading at $34.85, down about 10 percent from its previous close. Its highest point so far is $45.98.
Incorporated in 1998, NetSuite sells ERP (enterprise resource planning), CRM (customer relationship management) and e-commerce applications on a hosted, subscription-based model, in which customers access the software via the Internet and don't need to install it on their premises.
This software-as-a-service model, championed by companies like Salesforce.com and Google, is considered a significant threat to the traditional approach from vendors like Microsoft of having customers implement software on their own PCs and servers.
As of Sept. 30 of this year, NetSuite had over 5,400 active customers, according to its IPO prospectus . In 2006, the company had revenue of $67.2 million and a net loss of $35.7 million. In the first nine months of this year, it generated $76.8 million in revenue and racked up a net loss of $20.6 million, according to the prospectus.
NetSuite plans to use its IPO proceeds to pay off an $8 million balance on a line of credit with Tako Ventures, an entity controlled by Oracle CEO Larry Ellison, and to possibly make acquisitions.
As of Nov. 30, Ellison controlled about 60 percent of NetSuite's outstanding stock -- some 31.9 million shares -- but Ellison transferred those shares into a holding company, NetSuite Restricted Holdings. The move is meant to "effectively eliminate" Ellison's voting power and avoid potential conflicts of interests, according to the prospectus.
NetSuite also plans to devote between $10 million and $15 million for capital expenditures, including the purchase of property, plant and equipment and the addition of a second data-center facility, and for working capital and other general purposes, including its international expansion. NetSuite currently provides its hosted applications out of a single data center, which the company admits in the prospectus is a risk that could harm its business should there be any service disruption at this facility.
NetSuite also said it may use a portion of the net proceeds to acquire other businesses, products or technologies, although it doesn't have any agreements or commitments for any specific acquisitions at the moment. The money it doesn't spend will be invested in short-term, interest-bearing investment grade securities.
Tropos Networks has set up a network of about 70 meshed Wi-Fi routers in Mecca, providing Hajjis with free Internet connectivity during their annual gathering
By Stephen Lawson, IDG News Service
December 19, 2007
http://www.infoworld.com/article/07/12/19/Wi-Fi-mesh-lights-up-Mecca-for-Hajj_1.html
The millions of pilgrims in Mecca this week for the Hajj, an annual gathering of Muslims, can stay connected thanks to a temporary Wi-Fi mesh network covering a large part of the city.
Hajjis, as the pilgrims are called, come to the city in Saudi Arabia from around the world for several days of religious rituals. More than 2 million gather each year. A network of about 70 meshed routers from Tropos Networks has been set up to provide free Internet connectivity, according to Denise Barton, director of marketing at Tropos. Users only have to register before using it. Barton believes it is the first public Wi-Fi network set up for the Hajj.
Mesh networks are well-suited to temporary deployments because they need fewer fixed-line connections than do traditional Wi-Fi systems. Packets can hop from one router to another until they reach one that's connected to a landline. The technology has also been used for permanent municipal Wi-Fi networks, including the one Google had built with Tropos equipment in its hometown of Mountain View, California.
Saudi Arabia's Communications and Information Technology Commission appointed an Internet service provider, Bayanat Al-Oula, to provide the temporary network. It was rolled out in less than 60 days with no help from Tropos personnel, Barton said. Aptilo Networks, a wireless-management software and services company based in Stockholm, is running the network as a managed service from its offices in Malaysia. This also helped Bayanat get the infrastructure up and running quickly, said Per Knutsson, Aptilo's co-founder and director of product development. Aptilo is handling user authentication, security, customer-support calls and other features, as well as setting up the portal visitors use to register for the network.
Aptilo and Tropos are no strangers to temporary Wi-Fi networks. Aptilo has managed systems for large sporting events, and in 2004 Tropos built a network in downtown Redwood City, California, for a high-profile murder case. The trial of Scott Peterson, who was convicted of killing his wife and their unborn child, drew massive public and media attention. The county court where the trial took place set up a temporary network with five surveillance cameras and five meshed routers for its own security needs and for reporters who descended on the area for several months.
The Mecca network is made up of Tropos 5210 mesh routers, which use IEEE 802.11a for mesh connections and can support users with 802.11a, b and g devices, Barton said. Such networks typically require between 20 and 40 routers per square mile, she said.
By Stephen Lawson, IDG News Service
December 19, 2007
http://www.infoworld.com/article/07/12/19/Wi-Fi-mesh-lights-up-Mecca-for-Hajj_1.html
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