Specifications

TNPP Overview
133
Multiport for TNPP and TAP Outdial
TNPP Overview
TNPP (Telocator Network Paging Protocol) provides a standard method of
communicating between paging systems. On the 2000 Series Paging Terminals, it is
implemented using the Multiport card running TNPP software.
TNPP was designed to allow the exchange of information between paging terminals,
typically this information consists of pages. TNPP is used to link cities together so paging
can cover a wider area. It has been used as a concentrator for display pages, where a
terminal with a set of local phone lines takes calls and uses TNPP to forward the pages to
a remote terminal, thereby avoiding the expense of many FX lines.
TNPP passes packets of information between systems. These packets are binary data sent
over a serial link. Each system that sends or receives TNPP packets is a node. A TNPP
network is formed when two or more nodes are connected to each other. Nodes are
connected by links, a link being the means that data is transferred between the terminals.
Each packet is given a destination code or address. This address is used by a node to
determine if the data should be used to cause a locally transmitted page, and also if the
packet should be passed along to other nodes in the network.
TNPP Details
A TNPP network may range from just a pair of terminals connected together, to more than
65,000 interconnected terminals. There is a great deal of flexibility in how the terminals
may be connected together. However, although there may be many paging terminals
connected together within a network, this does not mean that the terminals are all
connected with a common circuit. Rather the terminals are “daisy chained” together, with
a pair of nodes connected by each link. Pages are passed from terminal to terminal, in a
bucket brigade fashion, until they reach their destination.