0 comments
There are five different Networking Topologies :

A) Bus
B) Star
C) Ring
D) Mesh
E) Tree.
When networks are design using multiple topologies it is called Hybrid Networks, this concept is usually utilized in complex networks were larger number of computer clients are required.
Bus Topology:
Bus topology is one the easiest topologies to install, it does not require lots of cabling. There are two most popular Ethernet cable types which are used in this topology they are 10Base-2 and 10BaseT. Bus topology based networks works with very limited devices. It performs fine as long as computer count remain with in 12 – 15, problems occurs when number of computer increases.Bus topology uses one common cable (backbone) to connect all devices in the network in linear shape. Network interface cards of all network devices are attached to single communication medium backbone cable. When any computer sends out message in the network it is broadcasted in the entire network but only intended computer accepts the message and process it. Bus topology provide simplicity to the network, however there is big disadvantage of this topology, if main single network cable some how gets damaged, it will shut down the entire network no computer will run on network and no communication can be made among computers until backbone cable is replaced.

Ring Topology:

Ring topology is one of the old ways of building computer network design and it is pretty much obsolete. FDDI, SONET or Token Ring technologies are used to build ring technology. It is not widely popular in terms of usability but incase if you find it any where it will mostly be in schools or office buildings. In ring network topology computers and other networking devices are attached to each other in such a way that they have devices adjacent to each other (Left and right side). All messages are travelled in the same directory either clockwise or anticlockwise. In case of failure of any device or cable the whole network will be down and communication will not be possible.

Star Topology:
This is the most commonly used network topology design you will come across in LAN computer networks. In Star, all computers are connected to central device called hub, router or switches using Unshielded Twisted Pair (UTP) or Shielded Twisted Pair cables.In star topology, we require more connecting devices like routers, cables unlike in bus topology where entire network is supported by single backbone. The most practical point of Star topology success is that the entire network does not go down incase of failure of a computer or cable or device, it will only affect the computer whose wire failed rest of the network will be working fine. However, incase of failure of central communication device such as Hub, Router or Switch the entire network will collapse. Star topology is widely used in homes, offices and in buildings because of its commercial success.
Tree Topology:
Just as name suggest, the network design is little confusing and complex to understand at first but if we have better understanding of Star and Bus topologies then Tree is very simple. Tree topology is basically the mixture of many Star topology designs connected together using bus topology. Devices like Hub can be directly connected to Tree bus and each hub performs as root of a tree of the network devices. Tree topology is very dynamic in nature and it holds potential of expandability of networks far better than other topologies like Bus and Star.


Mesh Topology:


Mesh topology is designed over the concept of routing. Basically it uses router to choose the shortest distance for the destination. In topologies like star, bus etc, message is broadcasted to entire network and only intended computer accepts the message, but in mesh the message is only sent to the destination computer which finds its route it self with the help of router. Internet is based on mesh topology. Routers plays important role in mesh topology, routers are responsible to route the message to its destination address or computer. When every device is connected to every other device it is known as full mesh topology and if every device is connected indirectly to each other then it is called partial mesh topology.

Conclusion:


Topologies are essence of computer networks design. Efficent networks can only be built based on the complete knowledge and understanding of above mentioned topologies. Knowledge of every communication device is of equal importance to help you find the best option for your network requirements. Optimum networks can be built with complete knowledge and understanding of computer network devices and how they are designed, any mistake in choosing inappropriate techniques, device etc can only be the waste of time, resources and efforts.
0 comments
A short and idiosyncratic answer
Robert Bruner
Basically, topology is the modern version of geometry, the study of all different sorts of spaces. The thing that distinguishes different kinds of geometry from each other (including topology here as a kind of geometry) is in the kinds of transformations that are allowed before you really consider something changed. (This point of view was first suggested by Felix Klein, a famous German mathematician of the late 1800 and early 1900's.)
In ordinary Euclidean geometry, you can move things around and flip them over, but you can't stretch or bend them. This is called "congruence" in geometry class. Two things are congruent if you can lay one on top of the other in such a way that they exactly match.
In projective geometry, invented during the Renaissance to understand perspective drawing, two things are considered the same if they are both views of the same object. For example, look at a plate on a table from directly above the table, and the plate looks round, like a circle. But walk away a few feet and look at it, and it looks much wider than long, like an ellipse, because of the angle you're at. The ellipse and circle are projectively equivalent.
This is one reason it is hard to learn to draw. The eye and the mind work projectively. They look at this elliptical plate on the table, and think it's a circle, because they know what happens when you look at things at an angle like that. To learn to draw, you have to learn to draw an ellipse even though your mind is saying `circle', so you can draw what you really see, instead of `what you know it is'.
In topology, any continuous change which can be continuously undone is allowed. So a circle is the same as a triangle or a square, because you just `pull on' parts of the circle to make corners and then straighten the sides, to change a circle into a square. Then you just `smooth it out' to turn it back into a circle. These two processes are continuous in the sense that during each of them, nearby points at the start are still nearby at the end.
The circle isn't the same as a figure 8, because although you can squash the middle of a circle together to make it into a figure 8 continuously, when you try to undo it, you have to break the connection in the middle and this is discontinuous: points that are all near the center of the eight end up split into two batches, on opposite sides of the circle, far apart.
Another example: a plate and a bowl are the same topologically, because you can just flatten the bowl into the plate. At least, this is true if you use clay which is still soft and hasn't been fired yet. Once they're fired they become Euclidean rather than topological, because you can't flatten the bowl any longer without breaking it.
Topology is almost the most basic form of geometry there is. It is used in nearly all branches of mathematics in one form or another. There is an even more basic form of geometry called homotopy theory, which is what I actually study most of the time. We use topology to describe homotopy, but in homotopy theory we allow so many different transformations that the result is more like algebra than like topology. This turns out to be convenient though, because once it is a kind of algebra, you can do calculations, and really sort things out! And, surprisingly, many things depend only on this more basic structure (homotopy type), rather than on the topological type of the space, so the calculations turn out to be quite useful in solving problems in geometry of many sorts.
For a more extensive essay on this topic with charming diagrams, see Neil Strickland's answer, and for an index of related essays, see Don Davis's list.

Windows Server 2008 'The Last 32-bit Operating System'

0 comments

Windows Server 2008

'The Last 32-bit Operating System'


LOS ANGELES - During this morning keynote sessions at WinHEC 2007, Microsoft general manager for Windows Server Bill Laing officially proclaimed Windows Server 2008 "the last 32-bit operating system" the company will ever release, for either servers or clients.

"We're in the middle of a transition to 64-bit computing," Laing told this morning's audience. It was inevitable that this would happen, he went on, but now's as good a time as any given the fact that memory prices are continuing to fall. Historically the transitions to 16-bit and 32-bit computing were difficult to make, he said - perhaps he could have called them excruciating. "But once we get through it, you look back and realize all the benefits, and realize it was the right thing for the industry.



"Windows Server 2008 is the last 32-bit operating system that we'll produce," Laing then pronounced. "Post-2008, we will transition to 64-bit. Many Microsoft products are becoming 64-bit only today, because they're realizing the benefits of 64-bit computing. Exchange Server 2007, Windows Compute Cluster Server, and Windows Server Virtualization are all 64-bit only today, because they give significant benefits."

As testers begin installing Windows Server 2008 Beta 3, Laing noted, the company's noting a higher percentage of 64-bit adopters.

But what does this mean for operating system support down the road? If Laing's pronouncement holds true, even the Windows Server editions designated for home users (don't forget "Home Server" is a server) will be 64-bit only. That won't be a problem for system designers, though it may be a factor for individuals looking to build their own home servers on the cheap, perhaps using Gigabyte's upcoming Micro DTX form factor motherboards.

The roadmap for Windows Server as demonstrated by Microsoft's Bill Laing at WinHEC Day 2.

Future extensions to the Windows Server product line will also be 64-bit only apparently, including the new medium-sized business edition coming early next year, code-named "Centro," and its small business edition "Cougar" later in 2008. Currently the roadmap shows the R2 edition of WS2K8 showing up in 2009.

But service packs are also "inevitable." They're not considered releases (some reporters here asked the question a few times just to make sure), but rather extensions. They will have to support 32-bit installations already in the field.

Window Server 2008

0 comments













Windows Server 2008
This new Server operating system bases on source code of the Windows Vista Kernel and carries the internal version number 6.0, build 6001. The successor of Windows server 2003 was developed under the code name "Longhorn". The operating system Windows Server 2008 from Microsoft shall further increase the reliability and flexibility in the server environment. This happens by interesting functions, efficient tools and the implementation of innovatively security features. The known Aero interface of Windows Vista was left out. A existing server installation with Windows Server 2003 or Windows Server 2008 Release Candidate is cabable for an upgrade. It is recommended to have at least a 2 ghz processor, 2 gb RAM and 40 gb of free storage on the hard disk. A new special feature which was never available before in a Windows operating system is beside the option Complete Installation the Server Core InstallationHyper-V presupposes a x64 processor of AMD or Intel with virtualization technology and offers a installable virtualization solution during or optionally after the installation. Several instances of operating systems like Windows and Linux can be executed at the same time on a computer with that.

The 4 main versions of Windows Server 2008 are different in the versions for 32 bit and 64 bit systems. For Itamium based computer systems (IA-64) Microsoft offers an optimized version as Web Server and Application Server. The functional range varies depending on variant and covers up to 17 server roles.

Windows Server 2008 Standard supports up to 4 GB RAM in the 32-bit version and 32 GB RAM in the 64-bit version. The operating system supports up to 4 processors. 12 server roles are complete supported, 4 partial and Active Directory Federation Services (ADFS) are not supported.

Windows Server 2008 Enterprise supports up to 64 GB RAM in the 32-bit version and 2 TB RAM in the 64-bit version. The operating system supports up to 8 processors. As field of application this server platform is recommended for the securing of business critical applications in Clusters. All server roles are supported.

Windows Server 2008 Datacenter supports up to 64 GB RAM in the 32-bit version and 2 TB RAM in the 64-bit version. The operating system supports depending on hardware up to 64 processors. As field of application this server platform is recommended for Computer Centres and Clusters. The replace of working memory and processors is possible without shutdown of the running operating system. All server roles are supported.

Windows Web Server 2008 supports up to 4 GB RAM in the 32-bit version and 32 GB RAM in the 64-bit version. As field of application this server platform is recommended for Web Server and supports only this server role.

Product features of Windows Server 2008 (depending on version):
without the Windows user interface only with a command line. The administration is possible completely in booth variants, but the core installation is limited to 8 server roles.
  • Hyper-V, Windows Server Virtualization
  • PowerShell new command line
  • SMB 2.0 for faster file and printer access
  • User Interface like Windows Server 2003
  • "Bitlocker" for the complete encoding of the hard disk
  • Windows SharePoint Services 3.0
  • IIS 7.0 Webserver
  • RODC (Read Only Domain Controller)
  • NAP (Network Access Protection) to isolate unsafe clients
  • WDS (Windows Deployment Services)
  • WSRM (Windows System Resource Manager)
  • Windows Server Backup
  • NLB (Network Load Balancing)


The Windows Vista Service Pack 2 of 26th, 2009 brings the operating system up-to-date. In addition to the bug fixes, the Hyper-V virtualization solution is now an integral part of the operating system. With Windows Server 2008 Standard, an additional instance is already included in the license, even unlimited in the Windows Server 2008 Datacenter. The options for authentication over WebDAV redirector were increased and energy management improved. Backward compatibility to legacy terminal server of license keys with 512 bytes in size is now ensured. Older license keys of Citrix applications can now be also used to work on Windows Server 2008 Terminal Server.





Screenshots

Windows Server 2008 Operating System screenshot 1Windows Server 2008 Operating System screenshot 2Windows Server 2008 Operating System screenshot 3Windows Server 2008 Operating System screenshot 4
Windows Server 2008, Choice of the languageWindows Server 2008, Beginning the installationWindows Server 2008, Product activationWindows Server 2008, Choice of the Enterprise Vrsion
Windows Server 2008 Operating System screenshot 5Windows Server 2008 Operating System screenshot 6Windows Server 2008 Operating System screenshot 7Windows Server 2008 Operating System screenshot 8
Windows Server 2008, Licence agreementWindows Server 2008, New installation or upgradeWindows Server 2008, Target drive for installationWindows Server 2008, Files are copied
Windows Server 2008 Operating System screenshot 9Windows Server 2008 Operating System screenshot 10Windows Server 2008 Operating System screenshot 11Windows Server 2008 Operating System screenshot 12
Windows Server 2008, Login screenWindows Server 2008, Overview after installationWindows Server 2008, Choice of the Server ServicesWindows Server 2008, Description for IIS
Windows Server 2008 Operating System screenshot 13Windows Server 2008 Operating System screenshot 14Windows Server 2008 Operating System screenshot 15Windows Server 2008 Operating System screenshot 16
Windows Server 2008, Selecting the FeaturesWindows Server 2008, Description for DateiserverWindows Server 2008, Selecting the FeaturesWindows Server 2008, Confirm of the selected Services
Windows Server 2008 Operating System screenshot 17Windows Server 2008 Operating System screenshot 18Windows Server 2008 Operating System screenshot 19Windows Server 2008 Operating System screenshot 20
Windows Server 2008, Overview after ConfigurationWindows Server 2008, Startmenu with ToolsWindows Server 2008, Command promptWindows Server 2008, Internet Explorer with extended Security
Windows Server 2008 Operating System screenshot 21Windows Server 2008 Operating System screenshot 22Windows Server 2008 Operating System screenshot 23
Windows Server 2008, Service administrationWindows Server 2008, Windows Firewall with extended SecurityWindows Server 2008, Server Manager

Versions



DateVersion
2007 Oct.Windows Server 2008 Release Candidate 0
2007 Dec.Windows Server 2008 Release Candidate 1
2008 Feb.Windows Server 2008
2009 MayWindows Server 2008 Service Pack 2
2009 JulyWindows Server 2008 R2
 
Copyright © . Blogger Theme by BloggerThemes & newwpthemes Sponsored by Internet Entrepreneur