 Wysłany: Wto 4:20, 15 Mar 2011 Temat postu: air nike trainers 7005 |
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| TCP/IP architecture model
Unlike the ISO/OSI reference model, TCP/IP architecture is only divided into 4 layers. The exchange of information between the layers is again exactly defined and again,air nike trainers, each service uses the services of a lower level and provides its services to a higher layer. Network interface(Data link) layerNetwork layerTransport layerApplication layer Network interface layer The lowest layer of the TCP/IP model. Its task is to provide access to the transmission physical medium and it differs according to the implementation of the medium. Network layer The network layer provides network addressing, routing and datagram transmission. Used protocols that will be of interest further regarding DHCP are IP and ARP. IP protocol It is the basic protocol of the network layer and in general the internet as a whole. It sends datagrams, which are independent units that contain information about the destination, source and the sequence number of the datagram. The sequence number is used for message reconstruction,salvatore ferragamo outlets, since the delivery order of the datagrams might not be the same as their order in the message and delivery reliability isn��t guaranteed at all. IP protocol versions: IP v4 �C 32 bit addresses. Provides approximately 4 billion unique addresses which aren��t sufficient at present times. IP v6 �C 128 bit addresses. The transition to v6 will bring (is bringing) higher security, QoS, packet segmentation and many more IP addresses. (the transition from IP v4 to IP v6 must be supported by the system provider) ARP protocol The ARP abbreviation stands for Address Resolution Protocol. This protocol is used to find the physical address (MAC) based on a known IP address. If required ARP sends information concerning the wanted address to all the stations in the network �C Broadcast. The stations consequently answer with a message containing their MAC. If the wanted device/station is outside the node/segment, the appropriate router will answer instead of it. Transport layer The transport layer is implemented only in terminal devices and it adjusts the behavior of the network according to the requirements of the device/application. Application layer The application layer is composed of programs that use net services to fulfill the needs of users. Examples of specific protocols are for instance FTP,puma boots, DNS and DHCP. Application protocols use TCP,ferragamo shoes men, UDP or both services at the same time. So called ports are used to differentiate between application protocols, they represent a type of label of the application. It is possible to change the ports in the settings of the service, but each service has a default port that isn��t changed for most services and is used as an unwritten standard. FTP = 21DNS = 53DHCP = 67 + 68 Topics related articles： asics olympos shoes 1268 salvatore ferragamo outlet 0541 spyder jackets online store 2295 |
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