Glossary
GL-8 March 2001 3160-A2-GB24-10
PRM Performance Report Messages. Messages indicating the current state of a T1 line as
specified by ANSI-T1-403.
protocol A set of rules that determines the behavior of devices in achieving and maintaining
communication.
PSTN Public Switched Telephone Network. A network shared among many users who can use
telephones to establish connections between two points. Also known as dial network.
Ptrns branch Test Patterns branch of the DSU/CSU menu tree.
pulse density A measure of the number of ones (marks, pulses) in relation to the total number of bits
transmitted.
QRSS Quasi-Random Signal Source. A test pattern simulating a random pattern of digital ones
and zeros used to simulate normal transmission.
RAM Random-Access Memory. Read/write memory that is volatile and loses its contents when
power is removed.
register A part of the device’s memory that holds stored values.
Rel branch Release branch of the DSU/CSU menu tree.
reset An initialization of the device that occurs at power-up or in response to a reset command.
RFC Request for Comments. One of the documents published by the Internet Engineering Task
Force that describe Internet protocols and policies.
RIP Routing Information Protocol. A protocol for exchanging routing information.
RJ48C An 8-position modular connector.
RLB Repeater LoopBack. Loops the signal being sent to the network back to the DTE
Drop/Insert and data ports after it has passed through the framing circuitry of the device.
Rlpbk branch Remote Loopback branch of the DSU/CSU menu tree.
router A device that connects LANs by dynamically routing data according to destination and
available routes.
RS-232 An Electronic Industries Association’s standard for a low-speed, 25-position, DCE/DTE
interface.
RS-232-like MIB RFC 1659, which defines objects for managin g RS-232-type interfaces (e.g., RS-422,
RS-423, etc.) and supports synchronous data ports and management communication ports
on the device.
RS-449 An Electronic Industries Association’s standard for a general-purpose, 37-position,
DCE/DTE interface.
RTS Request to Send. A signal from the DTE to the device, indicating that the DTE has data to
send. V.24 circuit105.
RX Receive. To obtain transmitted signals.
RXC Receive Clock. V.24 circuit115.
RXD Received Data. Pin3 of the EIA-232 interface that is used by the DTE to receive data from
the modem. Conversely, the modem uses Pin3 to transmit data to the DTE.
SDCP Shared Diagnostic Control Panel. A feature that allows carrier-mounted de vice s to share the
same diagnostic control panel.
self-test A test that checks most hardware components when power is applied to the device or a
reset is initiated.