Lucent Technologies PacketStar PSAX User Manual page 318

Point-to-Point Protocol
A protocol that connects two nodes (for example, router-to-router and host-to-network) over both
synchronous and asynchronous circuits. PPP replaces Serial Line Interface Protocol (SLIP), an older
protocol.
polling
An access control method in which one master device, such as a NMS, queries other network
devices, and requests they transmit one at a time.
POTS
plain old telephone service. The basic service supplying standard, single-line telephones (with no
features like call waiting or call forwarding).
PRI
Primary Rate Interface. The ISDN equivalent of a T1 circuit. Delivered to the customer's premises, it
delivers 23 B+D channels at 1.544 Mbps. PRI enables IP connectivity to the PSTN.
PRI ISDN
Integrated Services Digital Network with Primary Rate Interface service. A network with 24
B (bearer) channels, each of which is a full 64,000 bps. One of these channels is typically used to
carry signaling information for the other 23 channels. In Europe, PRI ISDN is 30 bearer channels at
64 Kbps and two signaling channels, each at 64 Kbps.
primary rate interface
See PRI.
PRI Offload
A method for transferring internet data calls from a PSTN 5ESS switch to a PSAX system, which
sends them to ISP RASs and World Wide Web switches. Since Internet data calls are much longer
and have much bigger payloads than DS0 voice calls, this transfer frees PSTN circuits for shorter
voice calls and relieves PSTN network congestion.
private automatic branch exchange
See PBX.
private branch exchange
See PBX.
private line automatic ring-down service
See PLAR.
private network-to-network interface
See PNNI.
programmable read-only memory
See PROM.
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PSAX 6-Port DS1 IMA Module User Guide, Issue 1
PacketStar
Glossary-54
Release 8.0
255-700-268