Glossary
GL-4 April 2001 8000-A2-GB26-50
MVL modem An endpoint (customer premises) modem that provides high-speed Internet or corporate
LAN access over twisted-pair copper lines using MVL technology.
NAP Network Access Provider. The provider of the physical network that permits connection of
service subscribers to NSPs.
NHR Next Hop Router. The next router IP address to any given destination.
NMS Network Management System. A computer system used for monitoring and controlling
network devices.
NSP Network Service Provider. A local telephone compa ny or ISP that provi des net work se rvices
to subscribers.
NTP Network Time Protocol. A method for maintaining accurate local time with respect to radio
and atomic clocks on the Internet.
NVRAM Non-Volatile RAM.
OCD Out of Cell Delineation. When operating in direct mode, an OCD event is declared if seven
consecutive cells have header error control violations.
OpenLane DCE
Manager A proprietary network management program used with HP OpenView that helps a network
administrator manage SNMP devices.
packet A group of control and data characters that are switched as a unit within a communications
network.
PDU Protocol Data Unit. A message containing protocol-specific information.
PING Packet InterNet Groper. Used for testing and debugging networks, PING sends an echo
packet to the specified host, waits for a response, then reports the results of its operation.
Used as a verb, to PING means to use the program to verify the accessibility of a device.
The PING program is supported from both the DSL and MCC cards.
POTS Plain Old Telephone Service. Standard telephone service over the PSTN with an analog
bandwidth of less than 4 kHz.
POTS Splitter A device that filters out the DSL signal and allows the POTS frequencies to pass through.
PPP Point-to-Point Protocol. as specified by Internet RFC 1661.
Proxy ARP Proxy Address Resolution Protocol (ARP). A technique for using a single IP address for
multiple networks. A device responds to ARP requests with its own physical address, then
routes packets to the proper recipients.
PSTN Public Switched Telephone Network. A network shared among many users who can use
telephones to establish connections between two points. Also know as dial network.
RADSL Rate Adaptive Digital Subscriber Line. A technique for the use of an existing twisted-pair
line that permits simultaneous POTS and high-speed data communication at adaptive
symmetric and asymmetric rates.
rate adaption The ability to automatically adapt when the port speed is lower than the line speed.
ReachDSL A subscriber line technology providing up to 1 Mbps throughput. Compliant with ANSI
T1.417, ReachDSL guarantees a minimum rate of 256 kbps at 18 kft.
Router A device that connects LANs by dynamically routing data according to destination and
available routes.
Routing Table A table used by a node to route traffic to another node in the multiplexer network.
RTT Round Trip Time.
RTU Remote Termination Unit. A DSL device installed at the customer premises.