Supporting VoIP Solutions with Traffic-Engineered MPLS. … VoIP solution,
organizations must consider the following issues:

White Paper Juniper Networks, Inc. 1194 North Mathilda Avenue Sunnyvale, California 94089 USA 408.745.2000 1.888 JUNIPER www.juniper.net Voice Over IP 101 Undetanding the Basic Networking Functio, Components, and Signaling Protocols in VoIP Networks Part Number: 200087-002 May 2007 2 Voice Over IP 101 Copyright ©2007, Juniper Networks, Inc. Table of Contents Introduction ……………………………………………………………………………………………..3 Intended Reade……………………………………………………………………………………….3 VoIP Initiatives…………………………………………………………………………………………..3 Undetanding Basic PSTN and VoIP Network Functio…………………………………..5 Database Services …………………………………………………………………………………5 Signaling ……………………………………………………………………………………………..5 Call Connection and Audio Traport Mechanisms ……………………………………..5 CODEC Operatio ……………………………………………………………………………….6 Undetanding VoIP Solution Components …………………………………………………….6 VoIP Phones, Cooles and Other End-User Devices …………………………………..7 Call Processing Server/PBX …………………………………………………………………….7 Media/VoIP Gateways/Gatekeepe …………………………………………………………..8 The IP Network …………………………………………………………………………………….8 Session Border Controller Functionality…………………………………………………….8 Undetanding VoIP Signaling Protocols ………………………………………………………..9 Establishing VoIP Connectio with H.323…………………………………………………9 Establishing VoIP Connectio with SIP ………………………………………………10 Signaling Control Information Between VoIP Network Elements ………………… 11 An Early Approach: MGCP ……………………………………………………………….. 11 The Next Generation: Megaco/H.248 ………………………………………………….12 Handling VoIP Service Requirements ………………………………………………………….13 Minimizing Latency …………………………………………………………………………….13 Assessing packet creation latency……………………………………………………….13 Mitigating serialization delays…………………………………………………………….13 Calculating propagation delays…………………………………………………………..14 Mitigating queuing delays………………………………………………………………….14 Assessing packet forwarding delays…………………………………………………….14 Assessing the Impact of Jitter on Voice Quality ………………………………………..14 Calculating Bandwidth Requirements ……………………………………………………..15 A Sample Bandwidth Calculation………………………………………………………..15 Compeating for

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