Cambridge SoundWorks P460 manual Pnni, Pop, Pstn, Pvc

Glossary

PNNI

Private Network to Network Interface. The interswitch interface within a private ATM domain. The PNNI trunking protocol for hierarchal ATM-layer routing and QoS support.

POP

Post Office Protocol. Used to retrieve E-mail from a mail server. Most E-mail applications use the POP protocol, although some can use the newer IMAP (Internet Message Access Protocol). POP3, unlike earlier versions, can be used with or without SMTP.

Port

A physical port is a connecting component that allows a microprocessor to communicate with a compatible peripheral. A port is identified by a port number.

Protocol

A set of rules and conventions that governs how devices exchange data, especially across a network. Low level protocols define the electrical and physical standards to be observed, bit- and byte-ordering, the transmission, error detection, and correction of the bit stream. High level protocols deal with data formatting, including message syntax, terminal to computer dialogue, character sets, message sequencing, etc.

Protocol Stack

A layered set of protocols which work together to provide a set of network functions. Each intermediate layer uses the layer below it to provide a service to the layer above.

PSTN

Public Switched Telephone Network. The collection of interconnected systems operated by the various telephone companies and administrations around the world.

PVC

Permanent Virtual Circuit. A permanent, virtual connection established by the network management between an origin and a destination.

QoS

Quality of Service. A measure of performance for a transmission system that reflects the system’s transmission quality and service availability. QoS is used mainly in connection with ATM media.

Avaya P460 Reference Guide 207