[...]... integrating VoIP into an existing data network ■ Describe various types of voice gateways and how to use gateways in different IP telephony environments CHAPTER 1 Introducing Voice over IP Networks Voice over Internet Protocol (VoIP) allows a voice- enabled router to carry voice traffic, such as telephone calls and faxes, over an Internet Protocol (IP) network This chapter introduces the fundamentals of VoIP,... Guide: Cisco Voice over IP (CVOICE) Chapter 2 Considering VoIP Design Elements VoIP Fundamentals 55 IP Networking and Audio Clarity Audio Quality Measurement VoIP and QoS 55 55 61 63 Transporting Modulated Data over IP Networks 66 Understanding Fax/Modem Pass-Through, Relay, and Store and Forward 67 Modem Relay 71 Gateway Signaling Protocols and Fax Pass-Through and Relay DTMF Support 82 Processing Voice. .. of voice gateways, and how to use gateways in different IP telephony environments VoIP Fundamentals Voice over IP is also known as VoIP You might also hear VoIP referred to as IP Telephony Both terms refer to sending voice across an IP network However, the primary distinction revolves around the endpoints in use For example, in a VoIP network, traditional analog or digital circuits connect into an IP. .. this case, it might be more costeffective to use VoIP to place those calls across an IP network If the IP WAN becomes congested, calls can overflow into the PSTN, ensuring that no degradation occurs in voice quality 5 6 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE) ■ Security: Mechanisms in an IP network allow an administrator to ensure that IP conversations are secure Encryption of sensitive... customer care, and workforce optimization VoIP Overview VoIP is the family of technologies that allows IP networks to be used for voice applications, such as telephony, voice instant messaging, and teleconferencing VoIP defines a way to carry voice calls over an IP network, including the digitization and packetization of the voice streams IP Telephony VoIP standards create a telephony system where higher-level... Introducing the Cisco Unified Border Element Gateway Cisco Unified Border Element Overview 521 521 Cisco IOS Image Support for Cisco UBE Gateways Cisco UBE Gateways in Enterprise Environments Protocol Interworking on Cisco UBE Gateways Media Flows on Cisco UBE Gateways Codec Filtering on Cisco UBEs RSVP-Based CAC on Cisco UBEs 526 528 530 530 Cisco UBE Gateways and Gatekeeper Interworking Cisco UBE Gateway... Guide: Cisco Voice over IP (CVOICE) SIP Like the H.323 protocol, the SIP is a peer-to-peer protocol The configuration necessary for the gateway is relatively complex because the dial plan and route patterns need to be defined directly on the gateway Examples of SIP-capable devices are the Cisco 2800 Series and 3800 Series routers The SIP protocol is responsible for all the signaling between a Cisco. .. applications The Cisco Unified Communications System provides and maintains a high level of availability, quality of service (QoS), and security for the network 4 Authorized Self-Study Guide: Cisco Voice over IP (CVOICE) The Cisco Unified Communications System incorporates and integrates the following communications technologies: ■ IP telephony: IP telephony refers to technology that transmits voice communications... Cisco IP Phones and make them available at any desktop, counter, or location Components of a VoIP Network Figure 1-1 depicts the basic components of a packet voice network PSTN Application Server IP Backbone MCU V Router/ Gateway Call Agent IP Phone V Router/ Gatekeeper IP Phone Videoconference Station Figure 1-1 Components of a VoIP Network V Router/ Gateway PBX Chapter 1: Introducing Voice over IP. .. codec to convert an analog voice wave to a 64-kbps digitized voice stream In VoIP design, codecs might compress voice beyond the 64-kbps voice stream to allow more efficient use of network resources The most widely used codec in the WAN environment is G.729, which compresses the voice stream to 8 kbps Chapter 1: Introducing Voice over IP Networks VoIP Signaling Protocols VoIP uses several control and . Guide: Cisco Voice over IP (CVOICE) Contents Foreword xviii Introduction xix Chapter 1 Introducing Voice over IP Networks 3 VoIP Fundamentals 3 Cisco Unified. Development Learning @Cisco June 2008 xviii Authorized Self-Study Guide: Cisco Voice over IP (CVOICE) Introduction With the rapid adoption of Voice over IP (VoIP), many