Verilink XEL XSP-100 SHARK IAP (9SA-USRS-9.0R1.02) Product Manual User Manual
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Chapter 10
Chapter 10.Appendix A: Glossary
Appendix: 10-12
XEL P/N & Release: 9SA-USRS-9.0R1.02
SHARK™ IAD User's Guide
PDU
Protocol Data Unit.
PING
Packet INternet Groper. Utility program that uses an ICMP echo message and its reply to verify
that one network node can reach another. Often used to verify that two hosts can communicate
over a network.
PPP
Point-to-Point protocol. Provides a method for transmitting datagrams over serial router-to-router
or host-to-network connections using synchronous or asynchronous circuits. A protocol that
allows a computer to connect to a remote network or device over either a synchronous interface
or a standard dial-up telephone line and modem.
PPTP
Point-to-Point Tunneling Protocol. Uses VPN to enable secure remote access to corporate
networks over the Internet
PRI
Primary Rate Interface. PRI in the United States provides 23 B-channels with a D-channel
transmitting at 1544 kbps. European PRI has 30 B-channels with a D-channel and transmits at
2048 kbps.
PROTOCOL
Formal set of rules and conventions that specifies how information can be exchanged over a
network.
PSTN
Public Switched Telephone Network.
P
ULSE
D
ENSITY
The ratio of ones to zeros in a digital data stream. The ones density rule requires at least 3 ones
in a sampled byte of information.
PVC
Permanent Virtual Circuit. A PVC emulates a dedicated physical connection across a WAN.
- Q -
- R-
RAI
Remote Alarm Indication. A signal transmitted in the outgoing direction when a terminal
determines that if has lost the incoming signal. RAI is commonly called the Yellow Alarm
signal.
R
ED
A
LARM
In T1, a red alarm is generated when a locally detected error such as loss of synchronization
exists for 2.5 seconds.
REN
The Ringer Equivalency Number indicates the number of ringers that may be connected to a
single telephone line. If the number of ringers exceeds the REN of the line, some or all of the
ringers may not operate.
REPEATER
Device that regenerates and propagates electrical signals between two network segments. Also
known as a hub.
RFC
Request for Comment. A documentation mechanism for developing standards, procedures, and
specifications in the internet community. Set of documents that specify the conventions and