User's Guide for ZyXEL Omni 56K USB Modem
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Protocol A “language” for communicating on a network. Protocols are sets of standards or rules used
to define, format, and transmit data across a network. There are many different protocols
used on networks. For example, most web pages are transmitted using the HTTP protocol.
Proxy Server A server that performs network operations in lieu of other systems on the network. Proxy
Servers are most often used as part of a firewall to mask the identity of users inside a
corporate network yet still provide access to the Internet. When a user connects to a proxy
server, via a web browser or other networked application, he submits commands to the
proxy server. The server then submits those same commands to the Internet, yet without
revealing any information about the system that originally requested the information. Proxy
servers are an ideal way to also have all users on a corporate network channel through one
point for all external communications. Proxy servers can be configured to block certain
kinds of connections and stop some hacks.
PSTN Public Switched Telephone Network was put into place many years ago as a voice
telephone call-switching system. The system transmits voice calls as analog signals across
copper twisted cables from homes and businesses to neighborhood COs (central offices);
this is often called the local loop. The PSTN is a circuit-switched system, meaning that an
end-to-end private circuit is established between caller and called.
Public Domain A special form of distributing software. Public domain software authors make no claim to
commercialize their rights.
Public Key
Encryption System of encrypting electronic files using a key pair. The key pair contains a public key
used during encryption, and a corresponding private key used during decryption.
QUIET A state in the voice mode of ZyXEL modems. Quiet is detected after a long pause in voice
data.
RAM Random Access Memory – working memory. The modem uses it among many other uses
to store information on sent, but not yet acknowledged data.
Redundancy Extra data that does not generate additional information.
Remote Location The modem at the other end of the line (the one you are calling or that is calling).
Reset Return a device into a defined base status.
Retrain The re-initialization process a modem is doing with the remote modem when the receiving
condition becomes bad.
RFC An RFC (Request for Comments) is an Internet formal document or standard that is the
result of committee drafting and subsequent review by interested parties. Some RFCs are
informational in nature. Of those that are intended to become Internet standards, the final
version of the RFC becomes the standard and no further comments or changes are
permitted. Change can occur, however, through subsequent RFCs.
ROM Read Only Memory. The ROM holds the system software and the profiles and settings of
the modem (refer to EEPROM).
Router A device that connects two networks together. Routers monitor, direct, and filter
information that passes between these networks. Because of their location, routers are a
good place to install traffic or mail filters. Routers are also prone to attacks because they
contain a great deal of information about a network.
RS Abbreviation of recommended standard.