Jumat, 03 September 2010

Local area network providing data transmission


Local area network providing data transmission functions through different types of physical networks. Local area network operates at Layer 1 (physical layer) and 2 (data link layer) in the OSI reference model that works in synergy to carry out the task of forming data communication with a good design of your network environment. For more details, reference the OSI model this problem you can read in more detail in my article the other problems the OSI reference model.

Local area network (LAN) consists of computer, network interface card (NIC), networking media, network traffic control devices, and other network peripheral devices. LAN allows a business office that uses computer technology to share an efficient, such as files, printers, and allows communication of information such as e-mail, telephone VoIP, Skype, and other.

Local Area Network is designed to do the following:
Operate within the limits of geographic areas
Allows any user to access a wide bandwidth media
Providing full-time connectivity to local services
Connecting two adjacent tool-limited cable media / wireless

Local area network consisting of high-speed network infrastrucktur in one single location that is used to transmit application data and other data services. Local area network technology that is widely used on Ethernet technology that is used is because its cheap budget; easy to use and easy in maintenance and its ability to scale up to a Gigabite-speed network.

Any network device that is used on the network infrastructure local area network? network devices that operate at Layer 2 Data Link is the Bridge; Switch and ATM switches. Switch is a switching device is purely working on layer 2 Ethernet which allows more efficient use of bandwidth. This switch devices can localize the impact of the collision (collision) and data contention data (data that were all fighting street - mutually in two-way streets) in a network. This can be achieved by studying the device address (MAC address) dynamically in the local area network and only to deliver a data gram to the address of devices are eligible to receive only - according to the recipient address if the letter is written. What about Bridge? Bridge is the original definition of the functions that can be done by the switch. While ATM ATM switch is a device that has the ability to switch functions. While local area network devices that operate at Layer 1 is the hub or concentrator or repeater.
What are the Design a common local area network?
This above picture is a diagram of local area network with a small scale only consists of several client computer as a data server that also functions as a print server; Wins or even as a control as well. Simple measure of local area network is usually used in SOHO - small office home office.
This above picture is a local area network with medium size which can consist of three or more switches are mounted on one or more networks between buildings. We see that the system redundancy is not applied in this medium-scale networks.
Local area network which can luck far more complicated than the above diagram which is a large-scale local area network where the switch-2 is configuration such a way in a network with redundancy system by activating all the spanning tree protocol on switch-2 is so manual tuning of all switch.

Why none of the three hubs in the form of a series on local area network? Hub is no longer popular today, but more importantly is the reason that the hub is a device that has an ancient network of the most intelligent even though not able to use local area network bandwidth efficiently. For repeater hub that serves as many ports to share a limited bandwidth is shared among all devices connected, and form one collision domain and one broadcast domain - essentially in a single bandwidth. Things like this is what ultimately caused the number of data collision (crash data), timeout in the terminal and also the number of re-transmission of data.

Therefore, all local area network switch which is supposed to use much higher would increase the flow of Ethernet networks and far to reduce the data collision on a local area network. therefore, the following is the standard recommended by the switches used in local area network.
To connect desktop computers to use the minimum speed 100Mbps switch.
Use speed 1 Gigabite switch for server connections or inter-switch connections (up links).
Must support a command line switch for the Telnet utility; ie snmp-based management.
Supports spanning tree protocol.
Supports Virtual LAN (VLAN).
Supports tuning of STP per VLAN protocol.
Supports aggregation technology

VLANs can create a network segment can easily be made for management reasons or reasons of security. VLAN also allows high-density LAN switches are built using the same hardware. Some switches can also connect to each other in a transparent inter-VLAN using VLAN trunking protocol.
In this simple diagram above, the segmentation of local area network using a switch that supports VLANs. In our previous scenario, local area network at the department of Geology, Accounting and Workshop segmented using VLANs.