Netw 320 Lab 1

NETW320 – Converged Networks with Lab

Lab 1 Title: Silent Suppression

Objectives

In this lab, we will build a company intranet that consists of two locations, one located on the west coast and one located on the east coast. We will then configure the intranet to consist of data traffic and VoIP traffic and link the coast-to-coast network together via an IP network. We will then analyze two scenarios, one without silent suppression and one with silent suppression.

Terminal Course Objective 6: Analyze current VoIP technologies. The analysis will include a differentiation between IP telephony and VoIP, an evaluation of the requirements for implementing VoIP architectures, and an analysis of existing infrastructures to qualify VoIP deployment.

Lab Objective 6: Given a business situation, configure, implement, and manage devices in an existing infrastructure to qualify VoIP deployment.

Explanation and Background

In a network that transports voice traffic, specialized software can be used to help conserve bandwidth by detecting the times when the users are not talking and cutting off the packet transmission for these times of silence. This technique is known as silent suppression. The specific software used is known as voice activation detection (VAD). Normal conversations between users can consist of as much as 50% silent time. By stopping the generation and sending of silent packets, bandwidth is conserved because these silent packets send no useful information. This allows bandwidth that would have been used to send silent packets to be used by other applications. A WAN network that has many voice channels operating simultaneously can add up to quite a bit of bandwidth savings.

Voice activation detection can also be used to forward idle noise characteristics (sometimes called ambient or comfort noise) to a remote IP telephone. Without idle noise giving the illusion of a constant transmission stream during silence suppression, the listener would be likely...