A business network is a network composed of hundreds or thousands of stations work of everyone associated with WAN circuits over many states and / or countries. The components consist of network devices, circuits, servers, applications, security and management of the network that connect employees to support business processes. It is business processes that companies are profitable. The use of new technologies to reduce costs and increase revenue is a business strategy that many companies have used recently. This contrasts with the Internet service provider (ISP) market who are the companies whose business is to sell the infrastructure, hosting and application services to small, medium and large enterprises. Many companies now rely ISP in the company for some or all these components that make up an enterprise network. In general, all circuits are provisioned to the ISP. Some devices are ownership of ISP and the servers and applications can be all owned ISP if you have a hosting agreement with them that provides those services. Management and security of your network can be outsourced to an ISP, and that is becoming popular with many Fortune 500 companies. Examples are AT & T and IBM, which offer agreements with many services and outsourcing otions.
OSI Model as a phone call
The OSI model was developed years ago as a reference for the network protocol and application designers to develop products with an open standard. That would promote a standard for the development of devices network interfaces, applications and services that work together. It is a model rather than a specification as it defines the layers and layers of services for people and how it works each layer with the layer above and below it. This model is a representation of how a network operates much like a phone call. A telephone call from home to a particular destination requires a physical connection that electrically connects the two places. When you take the phone off the hook to make a call which is similar the physical layer and a layer 2 data link services. When you dial a number that is a layer 3 network services or phone number routing. When someone answered the telephone call which is similar to the layer 4 transport and service layer 5 sessions to talk and listen. The specific language is spoken presentation layer and 6 Application Layer 7 services. Currently, data networks applying similar design principles.
OSI Layers and its business network
Your desktop computer at work is connected to an application server on a physical medium such as unshielded twisted pair (UTP). This is a service layer signaling electrical switch your desktop to a campus and the campus of a switch to a server. Your network interface card connects your desktop screen for the cable network and uses a protocol Layer 2 data link such as Ethernet that provides a connection to the campus switch and defines the time desktop access to the network. Before sending the data, the desktop must know the address of the server you are sending data. This is a layer 3 network service. Layer 4 transport service provides a logical connection between the server and desktop to coordinate the flow of traffic. In addition to the layer 4 error correction and retransmission of packets if there are problems with data delivery. With the data connection is established 5th layer service that maintains a logical connection between the processes of implementation on the desktop and server. The format of data for a particular application is a layer of six presentation service. Many applications use their own format which is something you learn when you open files different word processing providers. The application interfaces with the OSI model Layer 7, which is the application layer. This level defines an API that applications use to develop specific applications that work with this issue. "
The development of open industry standards in the different layers of the OSI model has contributed to the proliferation of integrating multi-vendor networks. Examples the application layer services are FTP, Telnet, SNMP and many applications that are used in a typical network. Microsoft has done a lot of work to standardize its platform Windows API to application developers can write third party programs for that operating system. The review of Windows 2007, for example, you will notice that provides services in layers 3-7 of the OSI model. The argument could be that Microsoft is involved with layers 1 and 2 services and since there are some software drivers for interfaces network that are available to them.
When the client describes the Microsoft network software that runs on each desktop, is to describe all programs, such as protocol stacks, drivers, network interface card, and programs that integrate these elements. The network driver software is normally found in layer 1 through Layer 4, while application developers will concentrate on layers 5-7 of the OSI model. Note that the OSI model is a model suggesting that provides guidelines for developers of the network. Some network software programs such as SNA does not define a network layer 3. The result is that it is not routable and a service tunnel encapsulation be used in the router to send data over a network using a network layer and IP addresses. An example is the integration of SNA network that has a layer network with a Windows network using IP network services.
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Shaun Hummel is the author of several technical books and has a web site focused on technology solutions job search information and certifications.
Shaun Hummel, CCNP, is a Senior Network Engineer with 11 years experience in enterprise network planning, design, and implementation. He has worked for various private and public companies in Canada and the United States improving infrastructure, security, and management. He has written Network Planning and Design Guide, Cisco Wireless Network Design Guide and Network Assessment Guide. www.networkjobsolutions.com
