
Overview Installation Troubleshooting Contact FAQ Specifications Glossary License
Configuration: Basic Gateway TCP/IP Wireless Print Server USB
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datagram | In RFC 1594, a datagram is defined as “a | |||||
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| information to be routed from the source to the destination computer without reliance on earlier | |||
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| exchanges between this source and destination computer and the transporting network.” For the most | |||
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| part, it has been replaced by the term packet. | |||
default route | The route by which packets are forwarded when other routes in the routing table do not apply. | |||||
dB | decibel |
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dBc | Signal level expressed in dB relative to the unmodulated carrier level desired. | |||||
DBm | A unit of measurement referenced to one milliwatt across specified impedance. 0dBm = 1 milliwatt | |||||
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| across 75 ohms. |
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dBmV | Signal level expressed in dB as the ratio of the signal power in a | |||||
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| when 1 mV is across 75 ohms. |
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demodulation | An operation to restore a previously modulated wave and separate the multiple signals that were | |||||
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| combined and modulated on a subcarrier. |
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DHCP | A Dynamic Host Configuration Protocol server dynamically assigns IP addresses to client hosts on an | |||||
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| IP network. DHCP eliminates the need to manually assign static IP addresses by “leasing” an | |||
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| IP address and subnet mask to each client. It enables the automatic reuse of unused IP addresses: | |||
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| The SBG is simultaneously a DHCP client and a DHCP server. | |||
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| • A DHCP server at the cable system headend assigns a public IP address to the SBG1000 and | |||
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| optionally to clients on the SBG LAN. |
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| • The SBG contains a | |||
distortion | An undesired change in signal waveform within a transmission medium. A nonlinear reproduction of | |||||
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| the input waveform. |
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diversity | Two identical antennas located a small distance apart to reduce multipath distortion and improve | |||||
antennas | wireless reception. Properly placed diversity antennas improve SBG wireless reception. | |||||
DNS | The Domain Name System is the Internet system for converting domain names to IP addresses. A | |||||
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| DNS server contains a table matching domain names such as Internetname.com to IP addresses | |||
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| such as 192.169.9.1. When you access the | |||
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| displayed on the browser to the destination website IP address. The DNS lookup table is a distributed | |||
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| Internet database; no one DNS server lists all domain name to IP address matches. | |||
DOCSIS | The CableLabs | |||||
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| modems, gateways, and supporting equipment to deliver data between an HFC network and a | |||
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| computer systems or television sets. To emphasize its use as a cable modem standard, DOCSIS is | |||
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| now called CableLabs Certified Cable Modems. | |||
domain name | A unique name, such as motorola.com, that maps to an IP address. Domain names are typically much | |||||
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| easier to remember than are IP addresses. |
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| Method of representing an IP address or subnet mask using four decimal numbers called octets. Each | |||||
format | octet represents eight bits. |
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| In a class C IP address, the octets are “network.network.network.host.” The first three octets together | |||
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| represent the network address and the final octet is the host address. In the SBG LAN default | |||
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| configuration, 192.168.100 represents the network address. In the final octet, the host address can be | |||
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| from 2 to 254. |
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download | To copy a file from one computer to another. You can use the Internet to download files from a server | |||||
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| to a computer. A DOCSIS or | |||
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| from a TFTP server during |
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downstream | In a cable data network, the direction of data received by the computer from the Internet. | |||||
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| X | 128 | SBG1000 Wireless Cable Modem Gateway User Guide |
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