If computer networks are working well and we can only hope that most of the time, the inner workings of the system modules are transparent to the average user. The most common components in a computer network, not including the cable, "are" router "hub" and "switch". Many of these modules can be aesthetically similar. Each module is typically Ethernet ports (RJ45, which seems to connect a phone large) and LED display. However, theseForms> work differently, and it is important to understand the differences.
modern network hardware work on the "Open System Interconnection (OSI) standard. This standard defines how communication should be implemented in a network. By this standard, the modules from different vendors can coexist on the same network. Wireless Networks (WLAN) and 802.11x standard is an additional element of network systems.
If aMessage is sent from one computer to another, will be subdivided into parts. A basic level, the message of "1" and "0" bit is reduced. The next step is a group of bits as a "framework". A frame contains control information including the destination address, and error detection. The next step is a set of frames as a "package". The terms frame and packet are sometimes used interchangeably. If a message is sent through a complex network like the Internet, some packetsotherwise, and met at the destination.
Tracking error with two frames and packages used. The most common procedure is called "cyclic redundancy check (CRC). Sums CRC of all" 1 "in the frame or packet. This number in hex at the end of frame / packet is stored. On the receiving side, the process is repeated . If I have the two hexadecimal values, is the proof. Otherwise, the receiver requests that the sending device. Send Most of these functions are performed by modules integrated circuits (chips) on the network.
The Hub
The hub network is working on the first layer of the OSI, the process known as "physically." The hub is the simplest of the three;. Module A hub is not aware of the contents of the message that it processes the message as a bit '. It 'simply records the message and distribute it to everyone, even back in portthat your message hub "active", the electrical signal from the noise and amplify the clean signal before repeating hub "person" does not amplify the signals received, .. it only receives a signal and get the signal as a repeat for each port. The hubs are sometimes used to connect multiple computers to a printer.
The network switch
The power switch works on the second layer of the OSI standard, the so-called "Data Link Layer." The network ofSwitch, as the name suggests on, signaling pathways, so that a wire leading to a particular destination. A switch is to improve network performance, especially in networks with large numbers of computers. A switch has enough intelligence on board to mark the path to each destination. The switch operates a network of message frames.
When you connect a computer to a network switch, the switch records or Media Access Control address "MAC" ComputerNetwork Interface Card (NIC). This is called "ARP", such as address or protocol. If a frame is received for a specific computer, the switch sends the frame on this machine only. Preventing the streets of the network used by all frameworks, network resources are conserved. A computer can have a frame to send computer B, while at the same time, computer C computer sends a frame to D.
The network router
The network router is working on the thirdLayer of the OSI standard, called "Network Layer". A router is the name of a reference to his role. Routers are some of the same functions as switches, routers, but most often used two or more networks. For example, a router could) be used to connect a network with a conventional wireless LAN (Local Area Network. Another common use ") is a LAN connection to the Internet (a" Wide Area Network "or" WAN. In this role, theRouter uses Network Address Translation (NAT) so that all computers connected to LAN address can be a shared IP. A network router message packets. A router uses IP addresses to route packets between multiple networks.
A PC can be configured to handle the function of a router when you use the router software and two or more network interface cards (NIC) is. A separate network card for every needNetwork
A router is capable of advanced features, including a (Domain Host Control Protocol), DHCP server and firewall. A firewall protects your computer from potential threats from other computers on the network. The connection of multiple networks often requires the conversion of protocols.
A router is a versatile classification. Router can provide connectivity within agencies, between different locations, including businesses and the Internet.The largest routers combine Internet Service Providers are used in corporate networks of large size, or close a deal with satellite remote to a local company. Advanced routers are powerful computer, complete with microprocessors. Very sophisticated routers are used by the Internet to manage network traffic more efficiently.
A router maintains a table called "Routing Information Base (RIB), which tracks information on courses available. May be at the RIB (To be updated continually as conditions change) dynamic static (manually determined by a network administrator) o. A RIB is easily on a small LAN, but can be very complex and very large routers used on the Internet.
Summary
There are different types of network modules compared to the three discussed here, and may be significant overlap of roles. For example, an "intelligent hub" change many of the characteristics of a network.> Wireless Networks (WAN) have much in common with their cousins traditional LAN, but new security protocol networks and concerns specifically related to wireless interference. A single meeting roles may be combined in many network routers sometimes have components as the function of network switches.
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