Contents. Preface...xxix. Introduction...xxxv. Module 1 Telephony... 1

Transcription

1 Preface...xxix Prerequisites...xxix Who Should Study This Course?...xxx Key Topics...xxx Course Objectives...xxx Exam Objectives...xxxi How to Study...xxxi CACQ...xxxii How to Become CompTIA Certified...xxxii Introduction...xxxv Module 1 Telephony... 1 Introduction...1 Terms...1 Lesson 1 Telecommunications Traffic Engineering... 6 Trunks...6 Trunk Direction...7 Trunk Capacity...7 Trunk Transmission Type...8 Analog Transmission...8 Analog Bandwidth...9 Digital Transmission...9 Digital Bandwidth...11 Types of Trunks...12 Special Access Trunks...13 Tie Trunk...13 Private Lines...14 Foreign Exchange...14 Ring Down...15 Trunk Pricing...15 iii

2 Convergence+ Carried Load...16 Conversation Time...17 Operating Time...17 Holding Time...18 Constant Distribution...18 Exponential Distribution...18 Probability...19 Grade of Service...20 Trunk Usage Measurements...20 CCS...21 Erlang...21 The Erlang B Traffic Formula...22 Erlang C and Poisson Tables...23 Poisson: Immediate Redial...23 Erlang C: Infinite Queue...24 No Formula Is Perfect...24 Estimating Total System Capacity...24 Outbound Trunk Capacity...24 Tie Trunks...25 VoIP Link Capacity...26 PBX Processing Capacity...27 Adjusting To Changes...28 Data Prioritization...28 Protocol Reservation...29 Session Fairness...30 Traffic Shaping...30 Lesson 2 Voice System Fundamentals Legacy Hybrid and IP Telephony Systems...34 Key Systems...35 Key System Components...35 Cordless Key Systems...36 Limitations of Key Systems...37 Hybrid Systems...38 IP Telephony Systems...38 Voice Transmission Fundamentals...39 Encoding, Decoding, and Compression...40 Digitizing the Voice...40 Analog to Digital...41 DTMF Signaling...42 How a Call is Made...43 Dial Tone...44 Entering a Telephone Number...44 Call Routing...44 Ringing...46 Ending the Call...47 Long Distance Voice Routing...47 iv

3 Signaling...48 In-Band vs. Out-of-Band Signaling...48 Signaling System Lesson 3 Number and Dialing Plan Components Prefixes...52 Telephone Numbering System...52 The Dwindling Supply of Numbers...53 Assigning Telephone Numbers...54 Special Area Codes...54 Special NXX Codes...55 Special Information: Hearing-Impaired Services: Service Codes, or N11 Numbers...55 Toll-Free: 800, 888, 877, etc Premium: Services...56 Follow-Me: Number Formats...57 Number Blocking...57 Anonymous Call Blocking...57 Digit Translation...58 Toll Fraud...58 ENUM...61 Local Number Portability (LNP)...65 Emergency Service...68 Lesson 4 Converged Network Endpoints Voice Terminals...75 IP Phones...75 TDM Phones...76 Analog Phones...76 Dialup Hard Phone...77 PC-Based Soft Phones...77 Microphones and Headsets or Speakers...77 USB Hand Sets...78 SIP Phones...78 PDA Soft Phones...78 WiFi Phones...78 Summary Quiz Module 2 Network Engineering Introduction...89 Terms...90 v

4 Convergence+ Lesson 1 General QoS Concepts Network Requirements for Convergence Converged Network Architecture A Hybrid Approach to Convergence Parallel WAN Paths for QoS Application-Level QoS Voice Quality The QoS Parameters Bandwidth Throughput Delay Encoding, Decoding, and Compression Packetization Jitter Jitter Buffers Measuring Jitter Wander Packet Loss Availability Security IP Header Features ToS Field IntServ RSVP CBQ COPS MPLS Policy Routing RED WFQ WRED DiffServ DSCP Code Points PHB Standard PHBs Custom PHBs DiffServ Domains IP Precedence Traffic Prioritization Q VLAN Standard The VLAN Tag Q as an Architecture Q Protocols p Traffic Prioritization Standard Priority Tags and Traffic Classes How 802.1p Prioritizes Traffic Mapping 802.1p Traffic Prioritization to IP and ATM Networks vi

5 Using QoS to Optimize Voice Quality in VoIP Networks Lesson 2 Network Performance Network Performance Issues Voice Quality Encoding and Decoding Propagation Packetization Delay Jitter Voice Compression Latency Packet Loss Port Settings Bandwidth Network Capacity Baselining Tools for Testing Activity Design and Modeling Tools Simulation and Testing Tools Network Capacity Baselining Packet Capture Functions Network Baselining in Monitor Mode Troubleshooting in Analyzer Mode Basic Operation Building the Relational Names Database Interpreting the Baseline Bottlenecks Measuring Shared Resource Utilization Measurement Tools Performance Monitor Task Manager Network Monitor Applying the Tools Output: Baseline Report Network Throughput Bandwidth Point-To-Point Links Various Data Rates and Associated Applications Bottlenecks Response Time in a Client/Server Configuration NIC Delay Physical Media Delay Server Delay Public Network Delay CPU Utilization Link Utilization Capacity Bandwidth Throughput vii

6 Convergence+ Impact to the Network when Adding/Modifying Converged Applications Lesson 3 Switches LAN Switching LAN Switch Features Switching Techniques Cut-Through Store-and-Forward Ethernet Switch Bandwidth Multilayer Switch Technology Layer 2 Switches Layer 3 Switches Comparing Layer 3 Switches and Routers Examples of Layer 3 Switching Techniques Proprietary Methods Packet-by-Packet Switching Layer 4-7 Switches Multilayer Switches Process of Switching Frames Learning Network Addresses Frame Forwarding/Filtering Redundancy and Active Loops Spanning Tree Algorithm Selecting Switches Switch Configurations Switch Features and Backbone Switch Considerations Number of Ports Support for Mixed Data Link Protocols Virtual LAN Support Redundancy and Reliability Network Management PoE Summary of Switch Features Lesson 4 Physical and Logical Port Settings Features Common to Both User Datagram Protocol and Transmission Control Protocol Demultiplexing Based on Port Number Ports and Addressing Well-Known Port Numbers Lesson 5 Network Classifications and Topologies Network Classification PANs LANs Campus Networks viii

7 MANs WANs GANs Network Topologies Bus Topology Star Topology Ring Topology Star Ring Topology Point to Point Topology Partial Mesh Topology Fully Meshed Topology Network Cloud Lesson 6 Routing Introduction to Routers How Routers Work Multiprotocol Routing How Routers Move Packets Between Networks Routers Rebuild Frames Internet Routers Broadcast Domains Routers for Broadcast Containment Router Advantages and Disadvantages Routing Tables Building the Routing Table Sample Network Routing Table Determining the Best Path Related Devices Brouters Direct Routing Indirect Routing Static Routing Default Routes Dynamic Routing Lesson 7 Protocols The TCP/IP Protocol Suite TCP/IP Protocol Layers and the OSI Model Network Interface Layer Protocols Internetwork Layer Protocols Transport Layer Protocols Application Layer Protocols Communication Using TCP/IP Application Layer Transport Layer Network Layer Network Interface Layer Destination Station ix

8 Convergence+ Features Common to Both UDP and TCP UDP UDP Service Demultiplexing Based on Port Number UDP Port Numbers Frame Encapsulation TCP Basic Data Transfer Reliable and Sequenced Packet Delivery Flow Control Multiplexing and Demultiplexing Connection Establishment Sockets IP Overview of IP IP Header Format and Field Descriptions IP Packet Encapsulation Real-time Transport Protocol Time Stamping Sequencing Compressed RTP How crtp Works Routing crtp Traffic Real-Time Transport Control Protocol Lesson 8 Transmission Mediums Cables Copper Cable Coaxial Cable Base Base Coaxial Cabling Characteristics Twisted Pair Cabling UTP Cable STP Cable USB Cables IEEE 1394 FireWire Cable Other Twisted Pair Cabling Characteristics Fiber Optic Cable Digital Subscriber Line How DSL Works DSL Physical Requirements Satellites Geosynchronous Satellites Low Earth Orbit Satellites Wireless Transmission How Wireless Transmission Works The Electromagnetic Spectrum x

9 Competition for the Finite RF Spectrum Wireless Networking Applications Point-to-Point Microwave Systems Cellular Systems and Personal Communication Services Wireless LANs Short-Range Infrared Transmission Ethernet Advantages and Disadvantages of Ethernet Ethernet Configurations Fast Ethernet Gigabit Ethernet Evolution-Data Optimized (EVDO) Cable Applications Coaxial Cable Applications Optical Fiber Applications Twisted Pair Cable Applications WLAN Applications Comparing Media General Installation Guidelines Virtual Private Networks (VPNs) VPNs in Action VPN Protocols Point to Point Tunneling Protocol (PPTP) Layer 2 Tunneling Protocol (L2TP) PPP Authentication Protocols Lesson 9 Signaling Basics Types of Signals Supervisory Signals Loop Start Ground Start E&M Emulated Tie Trunks Wink Start Digital Signaling Address Signals Dial Pulse Signaling Dual Tone Multifrequency Signaling Alerting Signals Control Signals In-Band vs. Out-of-Band Signaling Lesson 10 Methods of Encoding, Decoding and Compression Analog to Digital Voice Conversations Standards H H.264/MPEG-4/AVC xi

10 Convergence+ Audio Codecs G.711 Companding Algorithms G G.729a MPEG, MP MPEG.x MPEG MPEG MPEG-4 ALS Summary Quiz Module 3 Applications Introduction Terms Lesson 1 Messaging Applications Voice Mail Systems Voice Mail Features Voice Mail/PBX Integration Design Factors Unified Messaging Broadcasting Voice Mail Security Automated Attendants Text Messaging: , News, and Chat Addresses Protocols Simple Mail Transfer Protocol UNIX-to-UNIX Encoding Multipurpose Internet Mail Extension Secure/MIME Post Office Protocol Mail Server Configuration Store-and-Forward Mail Systems Chatting Instant Messaging Video Messaging Unified Messaging Benefits of Unified Messaging Unified Messaging Components Accessing Separate Message Sources Challenges xii

11 Lesson 2 Collaboration Applications Audio Conferencing Types of Audio Conferencing Audio Conference Connection Methods Internet Multimedia Basic IP Videoconferencing System Input: Microphone and Video Camera Webcams Video System Software Codec Types of Videoconferencing Systems ISDN-Based Video: H IP-Based Video: H H.320 vs. H Data Sharing Single or Dual Video Streams T.120 Series Lesson 3 Computer Telephony Integration and Call Center Automation CTI in Action Evolution of CTI Levels of Call Center Automation PBX/ACD Routing IVR Routing CTI Software Lesson 4 Computer Telephony Integration Concepts Media Processing and Call Control First-Party Call Control Third-Party Call Control CTI Components CTI Server CTI Client Applications CTI Link Key CTI Implementation Issues Key Integration Steps Enabling CTI in the Avaya Communication Manager MAPD Hardware ASAI Client Software Call Vectoring Software Lesson 5 Web-Enabled Call Centers Internet Callback Tailors Information for Each Customer Increases Site Revenue Captures Qualified Leads xiii

12 Convergence+ Uses Time Efficiently Callback Architectures Nonintegrated Callback Integrated Callback Web-Integrated Call Centers Implementation Issues Web Chats Customer Interaction Lesson 6 Call Routing Call Routing Patterns Reports Configurations Stand-Alone ACDs PC-Based ACDs UnPBX ACDs PBXs With ACD Functions Central Office-Based ACDs Nationwide Networks of ACDs Customer Handling Procedures Waiting Time Recorded Announcements On-Hold Entertainment Program Control Statements Telephone System Instructions Priority Queuing ANI Routing Elements of an ANI Transaction DNIS Routing ACD First Server First SBR Routing Rules Multiple Skill Queues Multiple Skills Vs. Multiple Queues SBR Simulations EBR Intelligent Call Queuing Call Queuing Call Recording Lesson 7 Interactive Voice Response Audio Computer Application Data Input Links to Outside Systems Data Output Audio Multimedia xiv

13 Trend Toward Integrated Solutions System Configurations Behind the ACD In Front of the ACD LAN-Based IVR Carrier-Based IVR Common IVR Mistakes Lesson 8 Mobility Components Softphone Application Layer Transport Layer Network Layer Network Interface Layer Destination Station Presence Cellular Integration Services Find-Me/Follow-Me: 500 Numbers Lesson 9 H.323 Standard for Packet Multimedia Overview of the H.323 Standard Version 1: Videophone Version 2: Packet-Based Multimedia Version 3: Under Development Other Standards of the H.323 Family Fundamental H.323 Network Components Terminals MCUs Gateways Gatekeepers MGCP MGCP Network Components MG MGC The H.323 Protocols and Their Effect on Voice Stream QoS H.323 Protocols Audio Codecs Silence Suppression G.711 Companding Algorithms MOS Audio Codec Delays DSPs DSP Delays RTP Time Stamping Sequencing ertcp xv

14 Convergence+ RAS: H Call Signaling: H Control Signaling: H H.323 Protocol Limitations Document Conferencing: T.120 Series Integration with the Digital PSTN ISDN/VoIP Integration Adding SS7 to VoIP Network Infrastructure Requirements Lesson 10 H.323 Call Processing H.323 Call Progression Phases Gatekeeper Discovery and Registration: H.225 RAS Call Setup and Signaling: H Control Signaling: H Call Termination: H.245/H H.323v2 faststart SIP SS7 to ITSP Call Progression Lesson 11 Session Initiation Protocol SIP SIP Messages Request Messages SIP Addresses Request Message Format Response Messages Response Message Format SIP Servers Proxy Redirect Registrar SIP Clients SDP Creating a SIP Session Lesson 12 Rich Media Transmission Methods Webcasting Audio and Video Streaming Unicasting vs. Multicasting (audio and video) Lesson 13 Video Standards H H H H.263 and H xvi

15 H.264 (MPEG-4 Part 10) or Advanced Video Coding (AVC) Advanced video coding for generic audiovisual services MPEG (MPEG-1, MPEG-2, MPEG-4) CIF/FCIF SIF QCIF HD G.711 Companding Algorithms G G.724 ADPCM G.729a Document Conferencing: T.120 Series ilbc NTSC PAL SECAM Summary Quiz Module 4 Hardware and Architecture Introduction Terms Lesson 1 The OSI Model Layers The Physical Layer A Stream of Bits The Data Link Layer Frames Across a Link Frame Addressing Data Link Layer Services On the Transmitting Node On the Receiving Node Data Link Layer Protocols Data Link Layer Sublayers The Network Layer Packets across a Network Network Layer vs. Data Link Layer Addresses Packet Routing Network Layer Services Network Layer Protocols The Transport Layer Transport Layer Services Transport Layer Protocols The Session Layer Session Layer Protocols xvii

16 Convergence+ The Presentation Layer Computer Number Systems The Binary Numbering System The Hexadecimal Numbering System The Application Layer Common Application Layer Programs USENET Newsgroups File Transfer and Access Virtual Terminals Web Browsers and Servers Lesson 2 Network Modules Centralized Network vs. Decentralized Network Configuration of Converged Application Resources Branch vs. Edge Network Solutions Network Flattening vs. Tier Network Lesson 3 Routers and Switches Routers Router Functionality Multiprotocol Routing How Routers Move Packets Between Networks Routers Rebuild Frames Internet Routers Broadcast Domains Routers for Broadcast Containment Router Advantages and Disadvantages Switches Managed vs. Unmanaged Switch Functionality Traffic Isolation With Switches Lesson 4 Media Servers S8700 Media Server Availability/Reliability Multi-Connect vs. IP-Connect Interoperability S S8300 Media Server with G700 Gateway Survivability S Lesson 5 Gateways Media Gateways G G G xviii

17 TDM/IP Gateway Traditional Separate Networks Partial Integration Networks How Packet Telephony Works Internet Telephony SIP Gateway Lesson 6 Gatekeepers Gatekeepers Lesson 7 Private Branch Exchange PBX Components Trunks Making a Call on a PBX Calling on an IP PBX Call Routing Supplementary PBX Features Direct Inward Dialing Direct Inward System Access PBX Enhancements Voice Response Voice Recognition Automatic Call Distributor Other Auxiliary Equipment Call Management System PBX Costs and Requirements Hybrid PBX IP Only PBX IP PBX Features Lesson 8 Router Firewalls LAN Firewalls Internet Firewalls Firewall Features Types of Firewalls Network Layer Firewalls Application Firewalls Hybrid Firewalls Lesson 9 CSU and DSU Channel Service Unit (CSU) Data Service Unit (DSU) Connecting to Digital Networks DTE/CSU Interface Smart Jack Subrate Facilities Digital Data Services (DDS) xix

18 Convergence+ Lesson 10 Network Termination Device One (NT1) NT1: Network Termination Device, Type Lesson 11 Admission Control and Traffic Shaping Admission Control Traffic Shaping Traffic Smoothing Traffic Burst Shaping Aggregated vs. Class-based Traffic Shaping Network Admission Policies Admission Control and Traffic Shaping Applications Lesson 12 Session Border Controller Session Border Controller Overview Types Install Locations Features Security Translation Lesson 13 In-line Power Components In-line Power Components (Power over Ethernet) PoE Lesson 14 Access Points What Is a Wireless Access Point? Wireless APs Access Point Modes Root Mode Bridge Mode Repeater Mode Common Access Point Options Fixed or Detachable Antennas Advanced Filtering Capabilities Removable (Modular) Radio Cards Variable Output Power Varied Types of Wired Connectivity Access Point Configuration and Management Mounting Lesson 15 Modems Modem Concepts Analog Modem Standards Cable Modem Technology How Cable Modems Work xx

19 Cable Modem Pros and Cons DSL xdsl Implementation xdsl Pros and Cons DSLAMs Summary Quiz Module 5 Management Introduction Terms Lesson 1 Converged Network Analysis and Problem Solving Network Troubleshooting Steps Identify the Exact Issue Re-create the Problem Isolate the Cause Formulate and Implement a Correction Test the Solution Document the Problem and Solution and Provide Feedback Troubleshooting Methods A Network Problem Example Digging Deeper The Fix Lesson 2 Common Symptoms and Problems Symptoms Poor Voice Quality MOS Clipping Echo Delay or Latency Audio Codec (Transcoding) Delays DSP DSP Delays Encoding, Decoding, and Compression Delays No Dial Tone Loss of Feature Set Crosstalk Dropped Calls Blocked Calls Erlang B Formula Poisson Formula: Immediate Redial Erlang C Formula: Infinite Queue xxi

20 Convergence+ Multiple Paths, Varied Traffic Poor Video Quality and Frame Loss Problems Media Errors Packet or Data Loss Protocol Overhead Protocol Mismatch Jitter Jitter Buffers Measuring Jitter Wander Port Settings Security Packet Re-ordering, MTU Issues, and Packetization Bandwidth Restrictions Throughput Hardware Failure Routing Misconfigurations QoS Tags Being Dropped IP Packet Loss Impact of Backup Over the Network Lesson 3 Network Performance Monitoring Tools LAN Monitoring Tools Baselining Software Tools for Baselining and Testing Built-In NOS Utilities Protocol Analyzers Types of Protocol Analyzers Components of a LAN Protocol Analyzer Protocol Analyzer Traces The Dark Side of Protocol Analysis Reading a Protocol Analyzer Trace SNMP SNMP Organization Architectural Elements Agents Management Information Base Agent Components Traffic Monitors SNMP Proxy Agents Manager Modes of Network Management Ping Ping Operation Pathping Pathping Command Syntax Pathping Example xxii

21 Traceroute How Tracert Works QoS Monitoring Tools LAN and WAN Bandwidth Monitoring Tools BERT Bit Error Rate Tester Testing Physical Media Copper Cables Tone Generator and Probe Media Tester/Certifier Lineman s Test Set (Butt Set) Optical Fiber Wireless LANs Voice/Video Quality Monitoring Tools Lesson 4 LAN Protocol Analyzer Operations Analyzers Overview Protocol Analyzer Features Display Filters Lesson 5 Traffic Management Data Sources Gathering Data Experiments Experimental Conditions Number of Experiments Sampling Bias Sample Size Sample Spread Planning a Study Lesson 6 QoS Parameters, Router Parameters, Load Balancing IP Header Features ToS Field IP Precedence DiffServ DSCP Code Points PHB Standard PHBs Custom PHBs DiffServ Domains IntServ RSVP CBQ COPS MPLS Policy Routing xxiii

22 Convergence+ PQ RED Traffic Shaping WFQ WRED Lesson 7 Mean Opinion Score Mean Opinion Score Lesson 8 Administration Tasks and Procedures Monitoring Log Files Reporting Managing Configuration Changes Policy Management (e.g., QoS, Admission Controls, Registration) Patching, Upgrades, and Backups Grandfather/Father/Son MAC (Moves, Adds, Changes) Call Detail Record Summary Quiz Module 6 Security Introduction Terms Lesson 1 Firewalls Firewalls Firewall Functions Firewalls Components Packet Filtering Router Application Level Gateways Circuit-level Gateway Bastion Host Screened Subnet Firewall Lesson 2 Internet Firewalls Types of Firewalls Network Layer Firewalls Application Firewalls Hybrid Firewalls Stance of a Firewall Everything Is Denied Unless Specifically Permitted Everything Is Permitted Unless Specifically Denied xxiv

23 Cost of a Firewall Components of a Firewall System Building Block: Packet-Filtering Router Service-Dependent Filtering Service-Independent Filtering Source IP Address Spoofing Attacks Benefits of Packet-Filtering Routers Limitations of Packet-Filtering Routers Example 1: Packet-Filtering Router Building Block: Application-Level Gateway (Proxy Server) Bastion Host Example 2: Telnet Proxy Benefits of Application-Level Gateways Limitations of Application-Level Gateways Building Block: Circuit-Level Gateway Example 3: Screened Host Firewall Example 4: Dual-Homed Bastion Host Example 5: Demilitarized Zone or Screened-Subnet Firewall Lesson 3 Authentication User Authentication Passwords Smart Cards Digital Certificates Biometric Authentication Message Digests and Digital Signatures Wireless Authentication IEEE 802.1x x Authentication on a Wireless Network EAP EAP Types Lesson 4 Proxies Web Servers Web Caching Proxy Servers Proxy Server Lesson 5 Virtual Private Networks VPNs in Action Why Enterprises are Using VPNs Tunneling: The Underlying Technology for VPNs Point-to-Point Tunneling Protocol (PPTP) Layer 2 Forwarding Protocol Layer 2 Tunneling Protocol xxv

24 Convergence+ PPP Authentication Protocols Internet Protocol Security Authentication Header (AH) Encapsulating Security Payload (ESP) Implementing IPSec Open Standards Help Ensure Interoperability Providing Effective Security User Authentication Extensible Authentication Protocol Token Card Support Data Encryption Symmetric (Private-Key) Encryption Asymmetric (Public-Key) Encryption Key Management Digital Certificates PPP Callback Control Filtering Firewalls and VPNs User Administration RADIUS Servers Directory Service Authentication, Authorization, and Accounting (AAA) Considerations For Choosing a VPN Solution VPN Tunnel Lesson 6 NAPT NAT What Is Address Reuse? A NAT Overview NAT Address Spaces IP Address Translation Static Address Translation Dynamic Address Translation Enhanced Network Security Masquerading/NAPT NAPT Even More Security Lesson 7 Encryption Commonly Used Encryption Systems Data Encryption Standard Secure Sockets Layer Message Digests and Digital Signatures Data Security Lesson 8 IDS and IPS IDS xxvi

25 Setting the Baseline IDS Features IDS Sensors IPS Types of IPSs Inline Network Intrusion Detection System Application Firewalls Layer 7 Switches Hybrid Switches Deceptive Applications Lesson 9 Antivirus Antivirus Malicious Programming Viruses Boot Sector Virus Multipartite Virus Macro Virus Stealth Virus Polymorphic Virus Virus Hoax Lesson 10 VLANs Switched VLANs Routed VLANs VLAN Tagging Q-1998 VLAN Tag ISL QoS p Traffic Prioritization p Traffic Classes, IPT U3, L The Future of VLANs Lesson 11 Demilitarized Zone Demilitarized Zone Screened Subnet Firewall Summary Quiz Glossary Course Quiz Index xxvii