A-Link RoadRunner 21, Полное руководство

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A-Link RoadRunner 21 Router 101
CO: Central Office: In a local loop, a Central Office is where home and office phone lines come together and
go through switching equipment to connect them to other Central Offices. The distance from the Central
Office determines whether or not an ADSL signal can be supported in a given line.
CPE: Customer Premises Equipment. This specifies equipment on the customer, or LAN, side.
CRC: Cyclic Redundancy Checking: A method for checking errors in a data transmission between two
computers. CRC applies a polynomial function (16 or 32-bit) to a block of data. The result of that polynomial is
appended to the data transmission. Upon receipt, the destination computer applies the same polynomial to
the block of data. If the host and destination computer share the same result, the transmission was
successful. Otherwise, the sender is notified to re-send the data block.
DHCP: Dynamic Host Configuration Protocol: A communications protocol that allows network administrators
to manage and assign IP addresses to computers within the network. DHCP provides a unique address to a
computer in the network which enables it to connect to the Internet through Internet Protocol (IP). DHCP can
lease and IP address or provide a permanent static address to those computers who need it (servers, etc.).
DMZ: Demilitarized Zone: A computer Host or network that acts as a neutral zone between a private network
and a public network. A DMZ prevents users outside of the private network from getting direct access to a
server or any computer within the private network. The outside user sends requests to the DMZ, and the DMZ
initiates sessions in the public network based on these requests. A DMZ cannot initiate a session in the
private network, it can only forward packets to the private network as they are requested.
DNS: Domain Name System: A method to locate and translate Domain Names into Internet Protocol (IP)
addresses, where a Domain Name is a simple and meaningful name for an Internet address.
DSL: Digital Subscriber Line: A technology that provides broadband connections over standard phone lines.
DSLAM: Digital Subscriber Line Access Multiplexer: Using multiplexing techniques, a DSLAM receives
signals from customer DSL lines and places the signals on a high-speed backbone line. DSLAMs are
typically located at a telephone company’s CO (Central Office).
Encapsulation: The inclusion of one data structure within another. For example, packets can be
encapsulated in an ATM frame during transfer.
FEC: Forward Error Correction: An error correction technique in which a data packet is processed through an
algorithm that adds extra error correcting bits to the packet. If the transmitted message is received in error,
these bits are used to correct the errored bits without retransmission.