Codan Radio P25 Training Guide - Manual (Page 27)

P25 RADIO SYSTEMS | TRAINING GUIDE
Chapter 2: P25 Interface Standards Page 19
TELEPHONE INTERCONNECT INTERFACE
P25 requires an open interface to telephone networks. The Telephone Interconnect Interface (Et)
supports both analog and ISDN telephone interfaces, providing for selective use of proven standard
telephone interfaces currently in use.
The Telephone Interconnect Interface defi nes a 2-wire loop start and a 2-wire ground start connection
between the RF Sub-System and the PSTN or a PABX. In addition, other optional interfaces may be
provided. The Telephone Interface deals only with voice service because it has been assumed that
circuit connected data services would access a telephone network via a modem and connect to a data
port on the radio system.
NETWORK MANAGEMENT INTERFACE
The Network Management Interface (En) is under development.
The Network Management Interface defi nes a network management interface to all RF Sub-
Systems. According to a single selected network management scheme within any RF Sub-System,
all fi ve classical elements of network management must be supported. It is expected that a network
management scheme will be selected that will bring with it the ability to manage RF Sub-Systems
with available network management system equipment. In addition, an existing network management
system, including computer and telecommunications equipment, may well be able to encompass P25
radio systems.
DATA HOST OR NETWORK INTERFACE
The Data Host or Network Interface (Ed) defi nes four different types of data connectivity. These include
a native open interface for connecting host computers, as well as the requirement to support three
different types of existing computer network interfacing (TCP/IP, SNA and X.25).