As computer networks are working well, and we hope, is the most time, the inner workings of the system modules are transparent to the average user. Not counting the most common components on a computer network cable, the "router", "hubs" and "switch". Many of these modules can be similar cosmetically. Each module typically has Ethernet ports (RJ45, which looks like an oversized phone plug) and LED displays. However, these modules can work differently, and itis important to understand the differences.
Modern network hardware is working on the "Open System Interconnection (OSI) standard. This standard defines how communication should be implemented in a network. By meet this standard, the modules can coexist in the same network from different manufacturers. Area networks (WiFi) and the standard 802.11X are an additional subset of network systems.
When a message is sent between computers, it will be divided into parts. Onthe basic level, the message is reduced to 1 "and" 0 "bits. The next stage is a set of bits as a" framework ". A frame contains control information including the destination address, and error detection. The next stage is a group of pictures as a "package". The terms frame and packet are sometimes used interchangeably. When a message is sent on a complex network like the Internet, some of the packets take a different route, and are recombined at the destination .
Error detection is usedwith two frames and packages. The most common is called "cyclic redundancy check (CRC). CRC sums of all "1" s in the frame or packet. This number is stored as a hexadecimal value at the end of the frame / packet. On the receiving side, the procedure will be repeated. When voting the two hexadecimal values, passes the test. If not, what device requires that the sending device again. Most of these functions are performed by integrated circuits (chips) inside the networkModules.
The Hub
The network hub is working on the first layer of the OSI standard, called the "physical layer". The Hub is the easiest of the three modules. A hub is not aware that the contents of the message are processed, it accepts the message as bits. It captures the signal and transfer it easily send to all, even back to the port that the message will be. An "active" Stroke is the electrical signal of the noise clean and amplify the signal before rebroadcast. A"receives not reinforce passive hub, the received signal, but only one signal and transmitting the signal as received at each port. Hubs are sometimes used to connect multiple computers to a printer.
The network switch
The network switch is working on the second layer of the OSI standard, the so-called "Data Link Layer." The network switch, as the name already mentioned, switches signal paths so that a wire goes to a specific target. A change to improve a networkPerformance, especially in networks with many computers. A change has enough on-board intelligence to remember the path to each destination to be. The network switch handles a message into frames.
If you change a computer to connect to a network, the switch of the Media Access Control or "MAC" address of the computer network interface card, registration card (NIC). This is called a protocol address, or "ARP". When a frame is received intended for a specific computer, it sends the switch frameworkonly on this computer. By preventing the network of paths that are used by each frame network conserving resources. A computer can be a framework to send computer B, computer C also is sending a frame to computer D
The network router
The network router is working on the third layer of the OSI standard, the so-called "Network Layer". A router's name is also a reference to his role. Some routers have the same opportunities asSwitches, routers, but are often used to connect two or more networks. For example, a router could be used to create a wireless network using a standard LAN connection (LAN). Another common use is to connect a LAN to the Internet (a "Wide-Area Network" or "WAN"). In this function, the router "Network Address Translation (NAT) so that all computers connected to the LAN can share a single IP address. A network of routers, the messagein packages. A router uses the IP addresses to route packets to them between different networks.
A PC can be configured to bypass the function of a router when using software router and two or more network interface cards (NIC). A separate network card is fitted, is required for each network.
A router is capable of advanced functions, such as a DHCP server (Domain Host Control Protocol) server and firewall. A firewall protects your computerof potential risks to other computers outside the network. Linking multiple networks often requires the conversion of protocols.
A router is an extremely diverse classification. Router can provide connectivity in offices, between different locations, and between businesses and the Internet. The largest routers connect Internet service providers, are used in very large enterprise networks, or close a deal with a satellite link to a removal companylocale. Advanced routers are powerful computers, complete with microprocessors. Very sophisticated routers are used by the Internet to manage the network traffic very efficiently.
A router maintains a table called "Routing Information Base (RIB) that contains information about the available routes title. The RIB can be static (manually by a network administrator defined) or dynamic (continually updated) to changing conditions. A RIB is on a small LAN is easy, but very complex in the very large routers used on the Internet.
Abstract
There are several types of network modules when the three discussed here, and there may be considerable overlap in roles. For example, an "intelligent hub can" many of the characteristics of a network switch have. Wireless Networks (WAN) have much in common with their conventional cousins, LAN, but additional protocol to the special security and interference concerns is specifically designed for> Wireless networks. Multiple roles can be consolidated into a single assembly. Network routers sometimes have to combine assemblies, as network switches.
No comments:
Post a Comment