ZyXEL Communications 642R Series manual Pstn, Pvc, Rfc, Rip, Sap, Snmp, Stp, Sua, Tcp, Tftp

Prestige 642R Series ADSL Router

PSTN	connections.
	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-
PVC	end private circuit is established between caller and callee.
	Permanent Virtual Circuit. A PVC is a logical point-to-point circuit between customer sites.
	PVCs are low-delay circuits because routing decisions do not need to be made along the
	way. Permanent means that the circuit is preprogrammed by the carrier as a path through the
RFC	network. It does not need to be set up or torn down for each session.
	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
RIP	permitted. Change can occur, however, through subsequent RFCs.
	Routing Information Protocol is an interior or intra-domain routing protocol that uses the
	distance-vector routing algorithms. RIP is used on the Internet and is common in the NetWare
SAP	environment as a method for exchanging routing information between routers.
	In NetWare, the SAP (Service Advertising Protocol) broadcasts information about available
	services on the network that other network devices can listen to. A server sends out SAP
	messages every 60 seconds. A server also sends out SAP messages to inform other devices
Server	that it is closing down. Workstations use SAP to find services they need on the network.
	A computer, or a software package, that provides a specific kind of service to client software
SNMP	running on other computers.
	System Network Management Protocol is a popular management protocol defined by the
	Internet community for TCP/IP networks. It is a communication protocol for collecting
STP	information from devices on the network.
	Twisted-pair cable consists of copper-core wires surrounded by an insulator. Two wires are
	twisted together to form a pair, and the pair form a balanced circuit. The twisting prevents
	interference problems. STP (shielded twisted-pair) provides protection against external
Straight	crosstalk.
	A cable that wires a pin to its equivalent pin. This cable connects two dissimilar devices, for
Through	example, a data terminal equipment (DTE) and a data communications equipment (DCE)
Ethernet	device. A straight through Ethernet cable is the most common cable used.
Cable
SUA	Single User Account. The Prestige's SUA (Single User Account) feature allows multiple user
TCP	Internet access for the cost of a single ISP account - see also NAT.
	Transmission Control Protocol handles flow control and packet recovery and IP providing
Telnet	basic addressing and packet-forwarding services.
	Telnet is the login and terminal emulation protocol common on the Internet and in UNIX
	environments. It operates over TCP/IP networks. Its primary function is to allow users to log
Terminal	into remote host systems.
	A device that allows you to send commands to a computer somewhere else. At a minimum,
Terminal	this usually means a keyboard and a display screen and some simple circuitry.
	Software that pretends to be (emulates) a physical terminal and allows you to type commands
Software	to a computer somewhere else.
TFTP	Trivial File Transfer Protocol is an Internet file transfer protocol similar to FTP (File Transfer

D Glossary