Netopia 4752, Руководство администратора

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Glossary 3
header: In packets, a header is par t of the envelope information that surrounds the actual data being
transmitted. In e-mail, a header is usually the address and routing information found at the top of messages.
hop: A single traverse from one node to another on a LAN.
hop count: The number of nodes (routers or other devices) a packet has gone through. If there are six routers
between source and destination nodes, the hop count for the packet will be six when it arrives at its destination
node. The maximum allowable hop count is usually 15.
host: A single, addressable device on a network. Computers, networked printers, and routers are hosts.
host computer: A communications device that enables users to run applications programs to per form such
functions as text editing, program execution, access to data bases, etc.
internet: A set of networks connected together by routers. This is a general term, not to be confused with the
large, multi-organizational collection of IP networks known as the Internet. An internet is sometimes also known
as an internetwork.
internet address, IP address: Any computing device that uses the Internet Protocol (IP) must be assigned an
internet or IP address. This is a 32-bit number assigned by the system administrator, usually written in the form
of 4 decimal fields separated by periods, e.g., 192.9.200.1. Par t of the internet address is the IP network
number (IP network address), and par t is the host address (IP host address). All machines on a given IP
network use the same IP network number, and each machine has a unique IP host address. The system
administrator sets the subnet mask to specify how much of the address is network number and how much is
host address. See also
Class A, B, and C networks .
Internet Protocol (IP) address: A network address that uniquely identifies a device on an IP network. This type
of address consists of 4 bytes, represented as decimal values, separated by periods, e.g., 192.168.2.143. All
IP addresses of the form 192.168.1.xxx are private IP addresses.
IP (Internet Protocol): A networking protocol developed for use on computer systems that use the UNIX
operating system. Often used with Ethernet cabling systems. In this manual, IP is used as an umbrella term to
cover all packets and networking operations that include the use of the Internet Protocol. See also
TCP/IP .
IP address, IP host address, IP network address: See internet address .
IP broadcast: See broadcast .
ISP (Internet service provider): A company that provides Internet-related ser vices. Most impor tantly, an ISP
provides Internet access ser vices and products to other companies and consumers.
ITU (International Telecommunication Union): United Nations specialized agency for telecommunications.
Successor to CCITT.
LAN (local area network): A privately owned network that offers high-speed communications channels to
connect information processing equipment in a limited geographic area.
Media Access Control (MAC) address: This 48 bit address is assigned by the device manufacturer for its
Ethernet connection. All Netopia 4752 units have MAC addresses of the form 00-C5-9X-XX-XX-XX. Each byte is
represented as a conventional two digit hexadecimal number.
MIB (management information base): A standardized structure for SNMP management information.
modem: A device used to conver t digital signals from a computer into analog signals that can be transmitted
across standard analog (not ISDN) telephone lines. Modem is a contraction of modulator-demodulator.