Table of Contents:

Definition and Overview

1. Introduction

2. PSTN Congestion: The Internet Brings the Network to Its Knees

3. Implications of Congestion to the PSTN

4. Evolution of Narrowband Off-Load: Moving the Problem Upstream

5. Preswitch Off-Load: Complete Relief to the Network

6. Preswitch Packetization: Relief, Economy, and the Foundation for Convergence

7. Off-Load Economics

8. Summary

Self-Test

Glossary

PDF of this tutorial

AGW - access gateway

CAGR - cumulative annual growth rate

CCS - centum call seconds

CO - central office

COBRAS - CO–based RAS

DSL - digital subscriber line

DSLAM - digital subscriber line access multiplexer

IN - intelligent network

ISP - Internet service provider

LATA - local access transport area

LNP - local number portability

PDN - public data network

PSTN - public switched telephone network

RAS - remote access server

TDM - time division multiplexing

TGW - trunking gateway

VoATM - voice over asynchronous transfer mode

VoFR - voice over frame relay

VoIP - voice over Internet protocol