NETW590/IP
Telephony/Voice Over
Internet Protocol (IP)

McGraw-Hill/Irwin

Copyright © 2011 by the McGraw-Hill Companies, Inc. All rights reserved.

Week 2
VoIP Fundamentals

McGraw-Hill/Irwin

Copyright © 2011 by the McGraw-Hill Companies, Inc. All rights reserved.

TCO B: Objectives
• Examine IP Telephony/VoIP fundamentals, including but not limited to: •
•
•
•
•
•

QoS
Codecs and Protocols
Terminology
Network Assessment
Applications
Architecture

1-3

TCO B: Key Concepts
• Explain how SIP sets up and tears down
VoIP calls.
• Determine how digitized voice is managed within a VoIP network.
• Analyze a simple VoIP network from end to end.
• Evaluate techniques for managing voice on a data network.

1-4

TCO C: Objectives
• Define the current use of the protocols that support IP Telephony/VoIP. Which ones are they? Do they interoperate
(play) together?

1-5

TCO C: Key Concepts
• Explain the function of TCP/IP as it relates to VoIP.
• Determine the role of codecs in both the
PSTN and VoIP.
• Analyze how PSTN and VoIP protocols interact in a hybrid system.
• Evaluate the importance of voice quality in a VoIP network.

1-6

TCO G: Objectives
• When looking at the following IP telephony/VoIP architectures, how does a firm decide on deploying one of them?
The architectures are:
• Hybrid
• H.323
• SIP

• Does each particular architecture have its own place, or is one determined to be the dominant architecture for IP
Telephony/VoIP deployments?
1-7

TCO G: Key Concepts
• Explain how voice quality is engineered in the PSTN.
• Explain the purpose of codecs.
• Analyze the advantages/disadvantages of using G.711 and G.728 & G.729 codecs for encoding voice.
• Explain how using PCM analog signals are converted to digital signals.

1-8

TCO B: Key Points
• A Codec: (Chapter 3)
• encodes analog voice into digital
• decodes digital signals into analog voice
• reconstructs the originally transmitted analog voice • Quantization refers to:
• the process of assigning binary values to sampled analog voice

• Categories of speech coding:
• Waveform codecs
• Multirate codecs
• Source coding
1-9

TCO C: Key Points
• The three main components of SIP: (Chapter 5)
• the UA, (User Agent)
• the SIP Registrar,
• the SIP Proxy Server

• Signaling protocols perform functions related to setting up and maintaining calls. The primary function performed includes: (Ch. 5)
• Session