Networks should be transparent to users. The network and distributed applications running on it must be as reliable as if they were running on the same computer. In addition, the network must provide self-healing capabilities that can redirect network traffic to broken cables and faulty components and be flexible enough to respond to changes related to the business in their environment.
Local networks were very simple, but now they represent different structures, at least five computational standards for transmissions and two standards for information necessary for network management. Local networks have become so complex that they need their own operating system.
The network is still the least understood and most important component in an organization’s information infrastructure. Most organizations committed to client / server computing agree that local area network bridging is not the place to go to save money. The advice is to try not to tie the connection. Local area networks with various platforms, such as hardware, software and operating systems.
Characteristics
1. Interconnected device
2. Trunk networks
3. Desktop High-Speed Local Area Network
Since local networks are distributed through the organization, bridges and routers are used to connect them. For example, a router can be used to move information between Ethernet, Token Ring, and fiber-distributed data networks. Users most likely will not understand the full 100MHz fiber-distributed data interface; because the router manages all connections.
Backbone networks also connect to local area networks, but also provide high-speed transmission and control of data flow between different networks. High-speed local area network connects computers directly to the network of fiber-optic data networks and, therefore, has access to a full transmission rate of 100 MHz. This configuration is intended for applications with a large amount of data, such as transmitted graphic data and images.
The two most common local area networks are the Ethernet token and the International Business Machine. Ethernet uses a coaxial baseband cable or a shielded pair wire and can operate at 10 MHz. Its protocol is multiple carrier multiple-access with collision detection.
This requires the sending device to track the network and send a message only in the sense that the network is not in use. If a collision is detected, the device should stop transmitting and try again when it finds out that the network is clean.
The token ring uses shielded pairs or optical cables and can operate at 4 or 16 MHz. Its protocol is called Token Ring. A special signal code, called a token, is transmitted from the stations to the station. If the device wants to send a message, it wants the marker to come, take it from the network and send it a message. The token returns to the network after the transfer is complete.
