63. Дүгнэлт
холбооны сүлжээний гол гол
хувилбарууд нь харилцаа холбооны
төхөөрөмжүүд, процессорууд, програм хангамж,
сувгууд, архитектуруудаас бүрдэнэ.
Харилцаа
Notas do Editor
If there are only 2 users on the network, it’s not very useful; if there are 200 it’s much more useful. So the Internet with millions of computers is incredibly useful.
Open systems provide greater connectivity. Open systems also provide high degree of interoperability.
Internet2 may never replace the Internet. May remain a scientific and government network.
With all these users, Metcalfe’s law suggests the possible connections are extraordinary
Two tiered client server includes just client and server Maybe connected to optional super servers
Thin client means that very little processing is done on the client. Most the processing is done on the server. Three-tier model includes thin clients, application servers and database servers
With a central server architecture, P2P file-sharing software connects your PC to a central server that contains a directory of all the other users in the network. When you request a file, the server searches the directory for any other users who have that file and are online. You click on list and make the P2P connection. Napster used this architecture. Pure P2P has no central directory or server.
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded) Coaxial cable from 200 million bits to over 500 million bits per second Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded) Coaxial cable from 200 million bits to over 500 million bits per second Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Twisted pair transmission speeds range from 2 million bits per second (unshielded) to 100 million bits (shielded) Coaxial cable from 200 million bits to over 500 million bits per second Fiber optic cable as high as trillions of bits per second. Uses light elements instead of electricity
Need to connect houses with a higher-speed technology. One solution is cable connection. Another solution is to skip the wires and use satellite or wireless.
Very thin client such as telephone, pager, PDA WAP: wireless application protocol WML: wireless markup language
Corporate LAN in upper left hand corner uses a hub to connect its multiple workstations to the network switch. The switch sends the signals to a series of switches and routers to get the data to its destination.
Two groups of layers. Upper four layers are used whenever a message passes from or to a user. Lower three layers are used when message passes through the host computer. If message is being sent to another host, it skips these layers. TCP/IP analogous to postal system. TCP: analogous to postal system and processes and protocols to use the mail. IP: analogous to zip code and address.
Bandwidth is sometimes called baud rate. Think of channel as a pipe with water in it. The wider the pipe, the more water that can flow through it. Narrow-band – unshielded twisted-pair Broadband – microwave, fiber optic or satellite
Circuit switching: telephone service Packet switching: Internet, x.25 protocols, ATM