DSP for Embedded and Real-Time Systems

CASE STUDY 3

Voice Over IP DSP Software System

Brief VoIP Domain Introduction

Wired TDM telecom network

The ‘Plain Old Telephone Service’ (or POTS) supplied the communication needs of the world for many decades during which it was refined and improved to a famous resilience known as ‘5-nines.’ People relied on their Public Switched Telephone Network (PSTN) which provided services 99.999% of the time. Such high availability meant that the downtime per year was of 5.26 minutes. To achieve such high availability the network had to implement many control protocols and build fault tolerance within. The PSTN consists of a series of Central Offices (CO), also known as End Offices or Class 5 switches on the edge of the network that served the end users ...