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Glossary
NRZI (Non Return to Zero Inverted) Encoding technique in which a change in state represents 0. Also known as
NSAP (Network Services Access Point) In the OSI environment, it is the SAP between the network and the transport layers. It identifies a Data Terminal Equipment by a unique address.
NT1 (Network Termination 1) The device that connects to your ISDN hardware and also works as a converter between an ISDN U- interface and an ISDN
NT2 (Network Termination 2) An NT2 handles termination for multiple B channels on a PRI line. NT2s are typically found embedded into PBXs or switches on network servers which support Primary Rate Interface (PRI).
OSI (Open Systems Interconnection) Model The
PABX Private Automatic Branch eXchange.
PBX (Private Branch eXchange) PBX is a private telephone switch. It is connected to groups of lines from one or more central offices and to all of the telephones at the location served by the PBX.
PCI (Peripheral Component Interconnect) Bus A
PDU (Protocol Data Unit) Data in a
PHY (Physical Layer) Layer 1 of the OSI model. Defines and handles the electrical and physical connections between systems. The Physical layer can also encode data in a form that is compatible with the medium (coaxial, twisted pair, fiber, and so on).
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