Voice/Data II





	Voice/Data II: Technology Options for Converged Networks Designing business-capable VOIP and converged networks requires a comprehensive understanding of the components, technologies, and the tradeoffs. Network professionals must be familiar with switching and routing technologies as well as the quality of service (QoS) functions that will be necessary to ensure enterprise grade voice services. This program is designed to provide you with the comprehensive background you will need to work effectively with both local and wide area VOIP systems. Who Should Attend Communications analysts/managers, equipment vendors, and carrier representatives who need a detailed, business-oriented understanding of VOIP applications, services, and technologies. What You Will Learn Prepare you with a detailed understanding of the technologies that are involved in VOIP and how they should be implemented to ensure an enterprise-grade VOIP solution. Review the OSI Reference Model and the major TCP/IP protocols that are used to support data and IP telephony, both media (e.g. RTP, UDP) and signaling (e.g. H.323, SIP). Overview the security issues surrounding IP telephony, the major vulnerabilities, attack strategies, and the essential elements in a defense in depth security strategy Describe in detail the technologies used in converged networks including packet shaping, QoS coordination, voice/video coding, signaling systems, and how they must be configured to insure optimal performance. Identify the major quality issues that come into play with IP telephony, the required performance levels we must maintain, and the standard mechanisms for measuring voice quality. Describe the configuration of hybrid versus IP PBX systems, and the issues involved in configuring local area networks to support voice services. Overview the 802.11/Wi-Fi technology used in wireless LANs, and identify the capacity, security, quality of service and other features required for WLAN voice. Compare the full range of wide area data services including MPLS VPNs, and their general capabilities, pricing elements, and their suitability for voice. Understand the overall process of troubleshooting a VOIP network, the types of tools that are available, the typical problems encountered, and their likely causes. Course Details 1. Voice System Configurations and Design Voice Network Services and Requirements Traditional Voice Switching Systems: PBX and KTS Trunks and Stations PBX versus Centrex System Features: Transfer, Conference, Call Forward, etc. Automatic Route Selection (ARS) Call Detail Recording (CDR) Integrated Components: Voicemail Automatic Call Distributors (ACDs) Interactive Voice Response (IVR) Automated Attendant Voice Network Services Network Interfaces: Analog Loop/Ground Start, DS-1, ISDN BRI/PRI Local Service Long Distance Options: Volume Discounts, Toll-Free, SDNs/VPNs Tie Lines: DS-1, PRI, Q.Sig Traffic Engineering for Voice Networks Traffic Engineering Terms and Concepts: Traffic Load, P-Grade of Service Traffic Engineering: Erlang B, C, and Extended Erlang B Conducting a Voice Traffic Study 2. The VOIP Market Fundamental Justification: Direct and Indirect Cost Savings Local VOIP Solutions IP PBX Hybrid IP PBX Voice over Wireless LANs Enterprise Wide Area VOIP Enterprise Router Networks Remote Access/Teleworker Solutions IP Trunking Service Unified Communications Systems (UCS) Concepts and Definition Major Components UCS Features: Presence Integrated Messaging Business Process Integration Consumer VOIP Cable Telephony, FTTx, Vonage, Skype Click-to-Call Services 3. TCP/IP Protocols for VOIP OSI Reference Model TCP/IP Model Application Protocols: FTP, SMTP/POP. Telnet, HTTP, RTP Transport Protocols: TCP, UDP Internetwork Protocols: IP, ICMP, ARP Network Access Protocols: Ethernet, Wi-Fi, PPP, Frame Relay, DOCSIS, etc. VOIP Protocols Media Transport: RTP, UDP, IP Signaling: H.323, SIP, MGCP (RFC 3435), Megaco (RFC 3425/H.248) Real time Transport Protocol (RTP) Operation Time Stamping, Sequencing Jitter Buffers: Fixed Adaptive Real Time Control Protocol (RTCP)/RTCP Extended Reports VOIP Signaling Protocols ISDN D Channel Signaling: Q.921, Q.931 Session Initiation Protocol (SIP) H.323 Megaco/H.248 Media Gateway Control Protocol (MGCP) 4. VOIP System Components User Devices IP/Ethernet Handsets Power over Ethernet (802.3af, 802.3at) SIP Phones Softphone Clients: Laptop, PDA Wi-Fi Handsets Wi-Fi/Cellular Handsets Telephony Server/Softswitch Packet Transport Network LAN Switch Wide Area Router Networks: Private Line, Frame Relay, IP, MPLS-VPN Gateways Trunk Gateway Station Gateway Other Elements Session Border Controller Multipoint Conferencing Unit (MCO) 5. VOIP Security Attack Techniques Dictionary Attack Brute Force Attack War Dialing Buffer Overflows Trojans Denial of Service/Distributed Denial of Service Spyware/Key Loggers Rootkits Phishing/Social Engineering Vulnerabilities Authentication Hijack Eavesdropping Signaling Manipulation ARP Poisoning/Man-in-the-Middle Worms, Viruses, Malware Theft of Service Spam over Internet Telephony (SPIT) Management Port Access Security Configuration Elements Firewalls DMZ/Screened Subnets Antivirus Software Network Access Control (NAC) Intrusion Detection/Intrusion Prevention Systems Encryption Key Features: Algorithm, Key Length, Key Refresh Algorithms: RC-4, DES, 3DES, AES Implementations: Secure Tunnel VPN, Secure Shell, Secure RTP, Wi-Fi (WEP, WPA, WPA/2) 6. VOIP Technologies Packet Network Characteristics Delay Jitter Packet Loss QoS Impact Voice Coding: Major Issues: Bit Rate, Delay, Loss Tolerance Encoding/Compression Techniques Pulse Code Modulation- G.711: A-Law, µ-Law ADPCM- G.726 Wideband: G.722 G.729A G.723.1 Video over IP Video Compression: Standard Definition, High Definition Bit Rates ISDN versus Packet-based Video Systems Video Coding Options: Analog: NTSC, PAL, SECAM MPEG2, MPEG3, MPEG4 H.320, H.323, H.261 (CIF, QCIF), H.262, H.263, H.264 T.120—Multimedia Conferencing 7. VOIP Quality Issues Voice Quality Measurements “Toll Quality” Absolute Category Rating: MOS Scores Perceptual Evaluation of Speech Quality (PESQ): ITU P.861, P.862, P.563 R-Factors ETSI TS 101 329-5, ITU G.107 Quality Issues In IP Telephony Sound Quality: Voice Coding/Packet Loss Transit Delay/Jitter Clipping Echo Control Other Quality Issues: Blocking, Dial Tone Delay, Disconnects, etc. 8. LAN Issues for IP PBX Systems LAN Infrastructure Fully Switched Configuration Power over Ethernet (802.3af/ax): Mid-Span versus End-Span Heat Dissipation Issues UPS/Battery Back-Up LAN Protocol Features Virtual LANs: 802.1q Priority: 802.1p IP PBX Configuration Hybrid PBX versus IP PBX Telephony Servers IP/Ethernet Handsets and Softphones Gateways: Trunk, Station Signaling Options, H.323, Session Initiation Protocol (SIP) Configuration Recommendations 9. WLANs for Voice WLAN Basics WLAN Configuration Options General Capabilities/Limitations Radio Links: 802.11a, b, g, and n WLAN Switches Network Design Configuration Options: Centralized, Distributed WLAN Voice Configuration WLAN Infrastructure Requirements Handsets Wi-Fi Wi-Fi/Cellular Softphones Technical Requirements for WLAN Voice Security Options: WEP, WPA, WPA2, 802.1x Quality of Service (QoS) Options: 802.11e/Wi-Fi Multi-Media (WMM), HCCA/ WMM-Scheduled Access SpectraLink Voice Priority (SVP) Meru's Air Traffic Control Other VoWLAN Issues Roaming Battery Life Call Access Control/Load Balancing WLAN Voice Configuration Recommendations 10. Implementing VOIP over Wide Area Services Packet Service Distinctions: Connection Oriented versus Connectionless Switched and Permanent Virtual Circuits (SVCs and PVCs) Best Effort versus QoS-Capable Packet Services Quality of Service Options Layer 2: 802.1p, 802.11e, DOCSIS Layer 3: DiffServ and MPLS QoS Mapping Requirements Private Line Transmission Rates DSUs/CSUs Frame Relay Network Configuration Performance Guarantees/Committed Information Rates Pricing Elements Implementing QoS Over Frame Relay Basic IP Service Best Effort Concept Security Requirements Using Basic Internet Service for VOIP MPLS Virtual Private Networks/RFC 2547bis Basic Concepts QoS Capabilities/Limitations Excess Traffic Handling Security Features Pricing Elements 11. Troubleshooting VOIP Networks Basic Tools Ping, Trace Route, SNMP, RMON QoS Measurement Tools Traffic Monitors Protocol Analyzers Symptoms: Poor call quality (Constant/Intermittent), delay, echo, clipping, one-way path, disconnects, wrong numbers, no service, blocked calls Problems: Transmission errors, packet loss, jitter buffer settings, configuration errors, port settings, QoS mapping errors, hardware failures, service failures, station class of service settings Problem logging, tracking, and follow-up procedures


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