Exam (elaborations) TEST BANK FOR CISCO TECHNICAL SOLUTION SERIES IP Telephony Solution Guide Version 2.1

Exam (elaborations) TEST BANK FOR CISCO TECHNICAL SOLUTION SERIES IP Telephony Solution Guide Version 2.1 CHAPTER 1 Introduction to IP Telephony 1-1 Overview 1-1 Organization 1-1 Audience 1-2 Scope 1-2 Revision History 1-2 Related Information 1-3 CHAPTER 2 IP Telephony Architecture Overview 2-1 CHAPTER 3 Planning the IP Telephony Network 3-1 In this Chapter 3-1 Related Information 3-1 Evaluating and Documenting the Existing Data Infrastructure 3-1 LAN/Campus Environment 3-2 WAN Environment 3-7 Evaluating and Documenting the Existing Telecom Infrastructure 3-10 Examining the Existing Telecom Topology 3-11 Examining PBX and Key Systems 3-12 Examining Voice Mail Systems 3-12 Examining Voice Trunking 3-12 Phones per Site and Phone Features 3-17 Examining the Existing Dial Plan 3-17 Fax Requirements 3-21 Evaluating and Documenting the Existing Power/Cabling Infrastructure 3-21 Data Center Power Requirements 3-22 Wiring Closet Power 3-23 IP Telephony Availability Requirements 3-24 Hardware Reliability 3-25 Software Reliability 3-26 Link/Carrier Availability 3-27 Power/Environment 3-29 Network Design 3-31 User Error and Process 3-33 Planning for WAN Deployments 3-34 Collecting Information on the Current WAN Environment 3-34 Determining Voice Bandwidth Requirements 3-38 Analyzing Upgrade Requirements 3-41 Contents iv Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Performing Upgrades and Implementing Tuning 3-43 Assessing Results 3-43 Operational Turnover and Production 3-44 Operations and Implementation Planning 3-44 IP Telephony Capacity Planning 3-44 Solution Manageability Requirements 3-48 Staffing and Expertise Requirements 3-51 Operations Support Plan 3-56 CHAPTER 4 Designing the IP Telephony Network 4-1 In this Chapter 4-1 Related Information 4-1 Overview 4-2 Introduction to IP Telephony Design 4-2 Designing the Campus Infrastructure 4-2 Designing for LAN/WAN QoS 4-2 The Importance of QoS 4-2 Connecting the IP Phone 4-8 Enabling the High Speed Campus 4-17 Building a Branch Office 4-42 Enabling the Wide Area Network 4-47 Summary 4-72 Designing Cisco CallManager Clusters 4-73 Selecting Gateways 4-73 Dial Plan Architecture and Configuration 4-73 Designing a Multi-site WAN with Distributed Call Processing 4-73 Designing a Multi-site WAN with Centralized Call Processing 4-73 Catalyst DSP Provisioning 4-73 Cisco Packet Fax and Modem Support Guidelines 4-73 Cisco IOS VoIP Router Gateways 4-74 Cisco VG200 4-75 Catalyst 6000 VoIP Gateways 4-76 DT-24+/DT-30+ Gateways 4-77 Future T.38 Fax-relay Support 4-77 E911 and 911 Emergency Services 4-78 Today’s E9-1-1 Service 4-78 IP Telephony Emergency Call Support 4-81 Security Considerations for IP Telephony Networks 4-86 Contents v Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Infrastructure Security Best Practices 4-87 Securing CallManager Servers 4-95 Integrating Voice Mail 4-107 Voice Messaging with Cisco uOne 4.1E 4-107 Integrating SMDI Voice Mail 4-108 Integrating SMDI Voice Mail Over IP WAN 4-139 Migrating to an IP Telephony Network 4-142 CHAPTER 5 Implementing the IP Telephony Network 5-1 In this Chapter 5-1 Related Information 5-1 Preparing for Implementation 5-2 General Site Information 5-2 Conducting the Site Survey 5-7 Site Survey Tables 5-7 Determining Site Requirements 5-9 LAN Requirements 5-9 WAN Requirements 5-10 Validating Implementation Readiness 5-18 Solution Design Review 5-19 Network Topology Analysis 5-19 Voice Network Analysis 5-19 Data Network Analysis 5-20 Solution Implementation Templates 5-24 Customer Ordered Equipment 5-30 Customer Premises Equipment (CPE) Interface 5-31 Customer Site Readiness 5-31 Implementing the Solution 5-31 Unpacking the Equipment 5-32 Verifying Cabinet Power Feeds, Rails, and Earthing 5-32 Physically Installing Equipment in Cabinet 5-32 Recording Equipment Serial Numbers 5-33 Verifying Equipment Slot Allocations 5-33 Installing Intra-Cabinet Power Cables 5-33 Installing Intra- and Inter-Cabinet Communications Cables 5-33 Verifying Circuit Termination in Customer Patch Panel 5-33 Powering Up Cisco Equipment 5-34 Verifying and Loading System Software and Firmware 5-34 Configuring the Equipment 5-34 Contents vi Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Implementing the Dial Plan 5-34 Configuring E-911 5-36 Conducting Installation Tests 5-47 Fallback Procedures 5-47 Implementing a Migration Strategy 5-47 Migrating from a TDM Network to Cisco IP Telephony Solution 5-48 Upgrading Cisco CallManager 5-48 Migration Phases 5-48 Solution Implementation Acceptance Testing 5-49 Verification Process 5-49 Acceptance Criteria 5-50 Post-implementation Documentation 5-51 Asset Tag and Cable Labeling 5-51 Customer Acceptance Certification 5-51 Completing the Implementation Reports 5-52 Case Studies 5-52 CHAPTER 6 Operating the IP Telephony Network 6-1 Related Information 6-1 Operations Support and Planning 6-1 Defining Technical Goals and Constraints 6-2 Service Level Goals 6-5 Determining the Relevant Parties 6-6 Defining Service Elements 6-6 Staffing and Support Model 6-23 Documenting and Approving the Operations Support Plan 6-25 Network Management 6-25 Functional Areas of Network Management 6-25 Network Management Solutions 6-26 Network Management Architecture 6-29 Managing Voice Over IP Network and Element Layers 6-32 NMS Reference Architecture 6-62 Managing Cisco CallManager with CISCO-CCM-MIB 6-65 Summary of IP Telephony Network Management Products 6-67 Securing IP Telephony Networks 6-68 Security Policy Best Practices 6-69 Establishing Physical Security 6-69 Protecting the Network Elements 6-70 Designing the IP Network 6-80 Contents vii Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Securing the CallManager Server 6-93 Troubleshooting IP Telephony Networks 6-103 Troubleshooting Tools 6-103 Troubleshooting Cisco CallManager Devices 6-115 Call Detail Records 6-167 APPENDIX A Cisco ICS 7750 and Cisco CallManager 3.1 A-1 IP Telephony Requirement Analysis A-1 Recommended Implementation Configurations A-2 Contents viii Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 C H A P T E R 1-1 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 1 Introduction to IP Telephony Overview The Cisco IP Telephony Solution Guide is intended to help organizations implement and manage IP Telephony network solutions, which includes Planning, Design, Implementation, and Operations network phases. This method is called the PDIO model. Cisco experts in IP Telephony design, network design, customer support, high availability, network management, network implementation, and traditional telecom systems collaborated to create this document so that you can reduce guesswork, technical resources, and the time needed to ensure successful implementation of a Cisco IP Telephony network. Organization This solution guide consists of the following sections: • Introduction to IP Telephony - provides a brief introduction to this manual. • Chapter 2, “IP Telephony Architecture Overview” provides a general description of the IP Telephony architecture. • Chapter 3, “Planning the IP Telephony Network” provides information necessary for planning IP Telephony solutions. • Chapter 4, “Designing the IP Telephony Network” provides detailed design specifications for building IP Telephony networks. • Chapter 5, “Implementing the IP Telephony Network” provides important information for successfully implementing IP Telephony. • Chapter 6, “Operating the IP Telephony Network” provides information for successfully operating, networking, securing, and troubleshooting IP Telephony networks. • Appendix A, “Cisco ICS 7750 and Cisco CallManager 3.1” provides IP Telephony information that is specific to Cisco Integrated Communications System 7750 (ICS 7750) and Cisco CallManager version 3.1 1-2 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 1 Introduction to IP Telephony Audience Audience The Cisco IP Telephony Solution Guide is intended for the following audiences: • Cisco customers involved with the planning, technical design, implementation, and operation of IP Telephony solutions • Technical management or network planning personnel • Cisco Sales Engineers, Technical Support Engineers, Cisco Professional Services, and Cisco Support Partners This document also assumes some technical knowledge of Cisco switching, routing, Quality of Service, CallManager functionality, gateway functionality, and voice signaling principles. Scope The Cisco IP Telephony Solution Guide discusses the core components of the IP Telephony network: • Current data network design for IP Telephony • CallManager version 3.0 • Gateways supported under the current IP Telephony architecture • Voice mail systems The following applications are not discussed: • uONE unified messaging • TAPI or JTAPI Contact your Cisco representative or visit the following Cisco website for available information on IP Telephony solution applications not covered in this solution guide: . Revision History Table 1-1 Cisco IP Telephony Solution Guide Revision History Version Date New/Changed Content Version 2.1 October 2001 • Added ICS 7750 information and IP Telephony case study links • Adjusted entries in Tables 3-19 • Added Appendix A Version 2.0 June 2001 Version 1.0 February 2001 1-3 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 1 Introduction to IP Telephony Related Information Related Information • IP Telephony Design Guide • IP Telephony Support Pages and Documentation 1-4 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 1 Introduction to IP Telephony Related Information C H A P T E R 2-1 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 2 IP Telephony Architecture Overview A previously published document, The Architecture for Voice, Video, and Integrated Data, can be found at the following C location: 2-2 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 2 IP Telephony Architecture Overview C H A P T E R 3-1 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 3 Planning the IP Telephony Network In this Chapter This chapter consists of the following sections: • Evaluating and Documenting the Existing Data Infrastructure • Evaluating and Documenting the Existing Telecom Infrastructure • Evaluating and Documenting the Existing Power/Cabling Infrastructure • IP Telephony Availability Requirements • Planning for WAN Deployments • Operations and Implementation Planning Related Information • Data Sheet: Cisco VoIP Readiness Net Audit Planning for Migration to IP Telephony • Cisco IP Telephony Network Design Guide • Westbay Engineers Limited Home Page • APC Home Page • Cisco IP Telephony Power Protection Page Evaluating and Documenting the Existing Data Infrastructure Organizations need to evaluate their existing data infrastructure to help determine upgrade requirements for the IP Telephony solution. You may need to provide infrastructure for additional bandwidth, consistent performance, or higher availability required for the converging environment. This section describes both LAN and WAN requirements. 3-2 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure You should document and evaluate the existing data infrastructure in terms of: • New voice performance requirements • Availability requirements • Feature requirements • Potential network capacity or impact. The required information for this includes network maps, device inventory information, and network baseline information. Analyzing these areas will help you understand the data network upgrade requirements needed to support IP Telephony and basic network availability, performance, and feature requirements. To evaluate voice performance requirements, review the device inventory, network design, and baseline information. Links and devices should have sufficient capacity for the additional voice traffic. You may need to upgrade links with high peak or busy hour utilization. Target devices with high CPU utilization, high backplane utilization, high memory utilization, queuing drops, or buffer misses for additional inspection and potential upgrade. Peak utilization characteristics in the baseline will be valuable in determining potential voice quality issues. To evaluate availability requirements for the IP Telephony network, review the network topology, feature capabilities, and protocol implementations. Review redundancy capabilities of the network to ensure you can meet availability goals with the current network design (or a new design) recommended for IP Telephony. To evaluate current feature capabilities of the network, evaluate device characteristics including a chassis, module, and software inventory. This will be useful in determining IP Telephony feature capabilities in the existing environment. You should also evaluate overall network capacity and impact to ensure that the network will meet overall capacity requirements and that there will be no impact on the existing network and application requirements. You should evaluate the network baseline in terms of the impact from IP Telephony requirements. You may need to add more CPU, memory, bandwidth, or features to ensure you meet both IP Telephony and existing network requirements. Note Cisco can provide an IP Telephony readiness audit that provides the recommended baseline information. LAN/Campus Environment We recommend a LAN/Campus analysis for all LAN environments involving any of the four IP Telephony deployment models that include: • Single site • Networked with PSTN • Multi-site with centralized call processing • Multi-site with distributed call processing. The LAN/Campus infrastructure analysis determines infrastructure and bandwidth issues that will affect IP Telephony voice quality and availability. You should collect the following types of information for the LAN/campus infrastructure analysis: • LAN/campus topology • IP addressing plan 3-3 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure • Location of TFTP servers, DNS servers, DHCP servers, firewalls, NAT (Network Address Translation) gateways, and PAT (Port Address Translation) gateways • Potential location of gateways and CallManager clusters • Protocol implementation including IP routing, Spanning Tree, VTP, IPX, and IBM protocols • Device analysis including software versions, modules, ports, speeds, and interfaces • Phone connection methodology (direct or daisy chain) • Baseline showing network and resource control plane use LAN/Campus Topology You normally build LAN/campus infrastructures using a hierarchical access, distribution, and core model. One or two of these layers may be collapsed into smaller LAN/Campus environments. However, in general, you will have a standard deployment model with a standard distribution and core configuration. Read the Campus Network Design document to review Cisco’s recommendations for a high availability campus design. This document can be found at the following location: http://cco/warp/public/779/largeent/design/campus_. You should create a simple map, such as Figure 3-1, that describes the layers, devices, media, and port speeds. The topology map should also show the location of TFTP servers, DNS servers, DHCP servers, firewalls, and gateways. Review the following LAN/campus topology issues: • Available average bandwidth • Available peak or burst bandwidth • Resource issues that may affect performance including buffers, memory, CPU, and queue depth • Network availability • IP phone port availability • Desktop/phone QoS between user and switch • CallManager availability • Network scalability with increased traffic, IP subnets, and features • Backup power capability • LAN QoS functionality • Convergence at Layers 2 and 3 3-4 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure Figure 3-1 LAN/Campus Topology IP Addressing Plan Review the following IP addressing plan and implementation characteristics: • Phone IP addressing plan • Average user IP subnet size use for the campus • Number of core routes • IP route summary plan • DHCP server plan (fixed and variable addressing) • DNS naming conventions Potential considerations with IP addressing include: • Route scalability with IP phones • IP subnet space allocation for phones • DHCP functionality with secondary addressing • IP subnet overlap • Duplicate IP addressing Location of Servers and Gateways Consider the location (or potential location) of servers and gateways prior to implementation and identify them in the LAN infrastructure planning phase as much as possible. Investigate other issues later to help ensure that service availability is consistent across the LAN infrastructure and for multiple sites. You should identify gateway and server network locations for the following: • TFTP servers • DNS servers • DHCP servers 6500 with IP routing and no 802.1q or VLANs Gigabit ethernet core links 100 megabit ethernet uplinks Catalyst 5500's with 1/2 user VLAN per device 10 megabit ethernet user access 100 megabit ethernet server access Gigabit ethernet distribution links 5500 with dual RSM VLAN support for access/distribution 48137 3-5 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure • Firewalls • NAT or PAT gateways • CallManager location • Gateway location Investigate these issues after you determine the location: • Network service availability • Gateway support (in conjunction with IP Telephony solution) • Available bandwidth and scalability • Service diversity Protocol Implementation Investigate overall protocol uses to determine IP Telephony scalability and any potential IP Telephony availability issues or additional protocol service issues. Review the following areas for the protocol implementation analysis: • IP routing including protocols, summarization methods, NBMA (non-broadcast media access) configurations, and routing protocol safeguards • Spanning Tree configuration including domain sizes, root designation, uplink fast, backbone fast, and priorities in relation to default gateways • HSRP configuration • VTP and VLAN configuration • IPX, DLSW, or other required protocol services including configuration and resource usage You should review the following issues in relation to protocol implementation: • Protocol scalability • Network availability • Potential impact on IP Telephony performance or availability Device Analysis Analyze the existing network devices to help identify hardware and software issues associated with the IP Telephony deployment. Many devices may not have the desired control plane resources, interface bandwidth, QoS functionality, or power management capabilities. The following table displays device attributes that may be important: • Device (type and product ID) • Software version(s) • Quantity deployed • Modules and redundancy • Services configured • User media and bandwidth • Uplink media and bandwidth • Switched vs. shared media 3-6 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure • Users per uplink and uplink load sharing/redundancy • Number of VLANS supported • Subnet size, devices per subnet Network Baseline You can use a network baseline of the existing campus/LAN infrastructure for IP Telephony capacity planning. This will help determine potential voice quality issues and the impact to the existing environment. Measure the following characteristics as part of the baseline: • Device average and peak CPU • Device average and peak memory • Peak backplane utilization • Average link utilization (prefer peak hour average for capacity planning) • Peak link utilization (prefer five minute average or smaller interval) • Peak queue depth • Buffer failures • Average and peak voice call response times (before IP Telephony implementation) Many different individuals and support organizations recommend different acceptable threshold values for these measured baseline issues. Remember that IP Telephony requires consistent performance and quality; therefore, all of the areas should be below safe recommended threshold values at all times. Use the following general guidelines on threshold issues: • CPU—A requirement for all background processing in addition to some traffic processing requirements. Background processing includes route updates, keepalives, network management, and other critical processes for keeping the network up and stable. During stressful network times, such as route convergence or link flapping, significant CPU will be used to ensure the network remains stable and intact. Because significant CPU can be used during stress situations, a good rule of thumb is 50% peak CPU and 30% average CPU. • Memory—Like CPU, main memory is used for background processing and traffic processing. And like CPU, significant amounts of memory can be used for a processing during link flap conditions, routing changes, and cache changes. Because significant changes can occur in memory requirements, a good rule of thumb is 50% peak and 30% average. • Backplane Utilization—Can be a major issue in some devices if the port speed and density is higher than the available backplane capabilities. Backplane utilization over 50% may also indicate some port queuing or dropped traffic for trunks that have less bandwidth than the sum of all downstream bandwidth. • Link Utilization—Critical to IP Telephony deployments because of VoIP performance and jitter requirements. First, remember that SNMP thresholds for peak utilization are still mainly done for five minute intervals. A good rule of thumb is to increase bandwidth utilization 40% above the five minute value to determine a true measure of peak utilization over the five minute average. Average link utilization may also be useless over time if peak-critical traffic occurs during a shorter interval of one hour. The telecom community thinks in terms of “busy hour” traffic. If you perform capacity planning using this busy hour utilization, then data network managers can consistently meet both voice and data requirements. To some extent, QoS capabilities at level II and level III will help minimize the need for significant bandwidth headroom. However, voice will add significant volume to the network and care should be taken to ensure that data traffic is not starved. Network designers also like to ensure that more 3-7 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure bandwidth is available towards the core to help minimize or eliminate significant or critical congestion problems. Therefore, care should be taken for all core network links that have peak utilization in excess of 50% and average utilization above 30%. VoIP will likely work if it is higher, but there will be more opportunity for potential intermittent bandwidth problems that will first affect the critical voice traffic. • Queue Depth—Indicates link congestion. Any transmit queues that experience any volume at all indicate that traffic is waiting. This directly impacts voice jitter and delay and indicates that link utilization is exceeding a peak recommended value. • Buffer Failures—Indicates a temporary inability to perform control processing in the device and should be investigated in terms of overall network health. Some buffer failure issues could impact VoIP quality and should be investigated. Note Cisco can provide a network baseline called the IP Telephony readiness Net Audit ( WAN Environment We recommend a WAN infrastructure analysis for multiple-site WANs with distributed call processing or multi-site IP WANs with centralized call processing. The WAN analysis determines infrastructure and bandwidth issues that will affect IP Telephony quality and reliability. You should collect the following information for the WAN environment analysis: • WAN topology • Location of gateways and servers • WAN protocols • Existing QoS requirements • Device Analysis including software versions, modules, ports, speeds and interfaces • WAN baseline Note Review “LAN/Campus Environment” for information on location of gateways, IP addressing plan, and protocol implementation. We recommend some LAN analysis for all WAN sites supporting IP Telephony. WAN Topology You normally build WAN topology infrastructures using a hub and spoke model, meshed multi-site model, or a combination of both. You should create a WAN diagram showing potential IP Telephony sites, WAN devices, remote LAN devices, interface types, and bandwidth. The map should show the location of DNS servers, DHCP servers, firewalls, gateways, and potential CallManager locations. See Figure 3-2 for a sample WAN topology. Review the following WAN topology issues: • WAN availability, including bandwidth redundancy and resiliency • WAN design or topology issues that may affect IP Telephony quality or performance 3-8 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure Note The Cisco IP Telephony Network Design Guide currently recommends a hub and spoke topology until call admission control using RSVP (Resource Reservation Protocol) is completely available. This document can be found at the following location: • WAN scalability with increased traffic, IP subnets, and features • Bandwidth and WAN service expectations • Existing QoS requirements (see the “Designing for LAN/WAN QoS” section on page 4-2 for more information.) Figure 3-2 WAN Infrastructure Location of Servers and Gateways Consider the location (or potential location) of servers and gateways in the WAN prior to implementation and identify them in the WAN infrastructure planning phase as much as possible. Identify the following gateway and server network locations: • TFTP servers • DNS servers • DHCP servers • Firewalls • NAT or PAT gateways • CallManager location • Gateway location You should investigate the following issues after you determine the location: • WAN outage impact and service diversity • Gateway support (in conjunction with IP Telephony) • Available bandwidth and scalability 48139 3640 router 1025 port/512 CIR 1025 port/512 CIR 1025 port/512 CIR 3640 router 3640 router 2948G 10 LAN switch megabit/ sec Frame relay cloud 7500 router 2 megabit/sec port 1024 CIR Call manager DNS server DHCP server 100 10 megabit/ sec 10 megabit/ sec 2948G LAN switch 2948G LAN switch 3-9 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Data Infrastructure WAN Protocols You should investigate WAN protocols for issues that may impact IP Telephony quality or issues that may be affected by additional voice services. In many cases, the WAN may require further optimization to better support IP Telephony traffic. NBMA (non-broadcast multiaccess) environments may also be susceptible to protocol issues and overall reliability that can affect voice quality. Investigate the following specific issues: • WAN IP protocol implementation and protocol overhead • IP multicast implementation • Carrier Service subscription rates including port speed, committed information rates, and expected performance • NBMA protocol issues affecting voice quality and performance • Other protocol overhead, including IPX and SNA Analyze the following areas after investigating WAN protocol issues: • Protocol optimization • WAN scalability with increased traffic • Expected network convergence with redundant topologies • Carrier reliability and quality expectations with WAN protocols Existing QoS Requirements You should evaluate existing WAN QoS requirements to determine compatibility with Voice QoS requirements. You should identify applications and performance requirements, including application performance, burst requirements, and batch requirements. Investigate the following areas: • Existing WAN QoS configurations • Critical application requirements, including raw performance, burst bandwidth, and batch bandwidth • WAN call admission control Device Analysis An analysis of existing network devices in the network helps identify hardware and software issues associated with the IP Telephony deployment. Software versions are important to determine QoS requirement compatibility. You can also use this information to create a network reliability path analysis to help determine potential network availability. The following table displays device attributes that may be important: • WAN Devices • Software Version(s) • Remote LAN Devices • Software Version(s) • Quantity Deployed • Modules and Redundancy • Services Configured 3-10 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure • WAN Media/Bandwidth • LAN Media/Bandwidth • Switched vs. Shared Media • User and IP Addressing per WAN Site WAN Baseline You can use a WAN baseline of the existing WAN and WAN site infrastructure for IP Telephony capacity planning. This will help determine potential voice quality issues and the impact to the existing environment. Measure the following characteristics as part of the baseline: • Device average and peak CPU • Device average and peak memory • Average link utilization (prefer peak hour average for capacity planning) • Peak link utilization (prefer five minute average or smaller interval) • Peak queue depth • Buffer failures • Average and peak voice call response times (before IP Telephony implementation) See the “Network Baseline” section on page 3-6 for specific guidelines for measuring these characteristics. Evaluating and Documenting the Existing Telecom Infrastructure You need to evaluate the existing Telecom infrastructure to help determine IP Telephony requirements. Perform this analysis for all sites implementing VoIP technology to determine the appropriate deployment model. IP Telephony supports the following deployment models: • Single-site deployment • Multiple single-site deployments interconnected via PSTN • Distributed IP Telephony sites with centralized call processing • Distributed IP Telephony sites with distributed call processing The Telecom infrastructure analysis examines the products, services, and features used in the existing telecom environment including: • PBX systems and locations • Voice mail systems and locations • Key systems • PBX inter-connectivity • Phone requirements • PSTN trunking • Voice mail trunking • Site-to-site trunking 3-11 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure The analysis will then help determine the IP Telephony design criteria. You should examine the following issues: • Existing PBX topology, including voice mail servers • PBX and Key Systems • Voice mail system • Voice trunking • Phones per site and phone features • Existing dial plan • Fax requirements Examining the Existing Telecom Topology The existing Telecom topology includes the location and internetworking connectivity for PBX systems, key systems, and voice mail servers. The topology should include the location of these devices and the trunks between systems used for connectivity. Trunking may include site-to-site trunks, PSTN trunks, and voice mail trunks. This section reviews the following existing Telecom topology issues: • PBX system connectivity overview • Trunking overview See Figure 3-3 for an example telecom topology showing PBX systems, key systems, and voice mail systems: Figure 3-3 Telecom Topology VPN PBX VPN PBX EPN PBX EPN PBX 30 analog trunks 30 analog trunks Voice mail Voice mail T-1 PRI T-1 PRI trunks 48138 Remote PBX Long distance PSTN Local PSTN 3-12 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure Examining PBX and Key Systems You need PBX and key system information to help understand current voice features and functionality. The following information will help determine required features and PBX-to-IP Telephony connectivity requirements. • PBX or KSU vendor and model • Quantity and locations of PBX/KSU systems • Release of software running on PBX or KSU • Quantity and location of PBXs with which IP Telephony may interface • Hardware models and revisions of installed cards • Software features currently deployed, which may include call setup, conferencing, call transfer, call hold, call park, calling line identity, and calling party name • Number of existing analog connections for each PBX or KSU and three expected to remain following deployment • Number of existing digital connections for each PBX/KSU and those that will remain • Number and capacity of ISDN trunks connected to each PBX Examining Voice Mail Systems You will need the following information to determine IP Telephony compatibility and feature capabilities: • Voice mail system models and vendor • Quantity and locations of voice mail systems • Hardware model and revision cards of voice mail systems • List of software features currently deployed with voice mail system • Does the voice mail system have an SMDI interface? • How is the voice mail system connected to the PBX? • Is the message waiting indicator integrated into the voice mail solution? Examining Voice Trunking Use the existing voice trunking to determine the IP Telephony gateway requirements. In general, you should identify the trunks for voice mail, PSTN connectivity, and site-to-site trunking requirements. In addition, define the existing blocking factor for potential capacity issues. Cisco recommends a blocking factor of one percent for IP Telephony trunking. You may wish to complete a traffic analysis to understand busy hour trunking for the various trunking applications. You can then use an Erlang-B calculator () to determine new trunking requirements. PBX vendors can normally provide busy hour statistics as a support service. Use Table 3-1 to help identify overall trunking: 3-13 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure You may also use the following tables for planning and configuring the gateway trunks. In some cases, you may move these trunk Demarc locations to co-exist with IP Telephony equipment. In addition, you should document support responsibility for WAN carrier services for use in physical design documents. Table 3-1 Trunking Matrix Digital or Analog Two-way Calling DID Trunks DOD Trunks Voice Mail Trunks Local PSTN Trunks LD PSTN Trunks Trunks to Site X Trunks to Site Y Trunks to Site Z 3-14 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure Table 3-2 PBX WAN Trunk Information Local Site A Name: Item No. Local Location A Remote Location B Type (see below) Speed (Kbps) Framing Coding Local CSU/DSU A Vendor and Model Remote CSU/DSU B Vendor and Model 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Table 3-3 PBX WAN Trunk Cable Infrastructure Information Local Site A Name: Item No. PBX A Slot No./Port No. PBX A Connector Type - Gender PBX A/CSU Cable Length (ft.) CSU A DTE Connector Type - Gender CSU NET A Connector Type - Gender CSU to Demarc Cable Length (ft.) Demarc Connector Type - Gender Remote PBX B Slot No./Port No. 1. 2. 3. 3-15 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure Note When ordering your DID, get a block of telephone (DID) numbers equal to or greater than the number of devices (phones, virtual phones, and H.323 devices such as NetMeeting) that will be connected to the network. 4. 5. 6. 7. 8. 9. 10. Table 3-3 PBX WAN Trunk Cable Infrastructure Information Local Site A Name: Table 3-4 PBX WAN Carrier and Circuit Information Local Site A Name: Item No. Local Carrier A Company Name Local Carrier A Circuit ID Long Haul Carrier Company Name Long Haul Carrier Circuit ID Remote Carrier B Company Name Remote Carrier B Circuit ID 1. 2. 3. 4. 5. 6. 7. 3-16 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure ISDN PRI is a common PBX WAN trunk type. The following parameters are typically used when provisioning a T-1 or E-1 PRI span: • Interface: ISDN Primary Rate Interface (PRI) • Frame Format: Extended Super Frame (ESF) • Line Encoding: B8ZS • Number of B-Channels: 23 and 30 for Euro • D-Channel: on channel 24th or Euro PRI it is the 16th • Line Use: Voice ISDN PRI provisioning also requires a switch type to be configured for Layer 3 protocols. There are four families of switch type protocols for PRI provisioning: • AT&T, 4ESS, 5ESS, NII Called NI2 (National Protocols) • DMS100 and DMS 250 (National Protocols) • EUROPEAN PRI • Custom 5ESS IntecomE Common switch types and Layer 3 protocols include the following switch types for well-known PBX systems: • Nortel (Meridian): 5ESS Custom NOTE: Gateway must be set to NETWORK • Lucent (Definity): 4ESS or 5ESS • MCI: DMS 250 • SPRINT: DMS 100 or DMS 250 • AT&T: 4ESS • Madge (Teleos) BOX: 5ESS Custom • Intecom: 5ESS Custom Common switch types and Layer 3 protocols for IXCs and inter-exchange carriers include the following: • AT&T: 4ESS • MCI or SPRINT: DMS250 • When connecting to a local CO switch use the following: • 5ESS (5E8 or 5E9) • DMS 100 • NII 8. 9. 10. Table 3-4 PBX WAN Carrier and Circuit Information Local Site A Name: 3-17 Cisco Technical Solution Series: IP Telephony Solution Guide Version 2.1 Chapter 3 Planning the IP Telephony Network Evaluating and Documenting the Existing Telecom Infrastructure • Hunt Sequence: Float, Flex, or Fixed • Out-pulse of digits: 4 is standard, but can be from 1 to 23 digits Phones per Site and Phone Features You will need the number of currently supported phones to properly size the CallManager platforms. You should identify phones that will convert to VoIP and potentially some analog phones for emergency and fax backup.You should also know the required phone features, which may include the following: • Speaker capability • Mute • Call hold • Call park • Call transfer • Calling line identity • Calling party name • Multi-party conferencing Examining the Existing Dial Plan Examine the existing dial plan architecture to understand the required call routing, abbreviated dialing, and route-group features for IP telephony migration. Call routing is used for PSTN or offnet access. Features associated with call routing include: • Redundant or back-up paths (transparent to the user) • Emergency dialing call patterns • Automatic call distribution • Call blocking where individual groups or numbers have limited offnet access. Automatic call distribution allows many agents to answer calls from one published number. Call blocking is used to limit access to certain numbers such as 900 toll numbers or long distance PSTN access from building lobby phones. Abbreviated dialing is used to reduce the number of digits required for extension calls. In many cases, local extension dialing has been reduced to 4-digit numbers. Questions for the IP Telephony deployment include: • Will the organization use existing or distributed dial plans among multiple sites? • Are there number ranges to be reserved for PBXs? If so, what are they? • Are there number ranges to be reserved for analog phones? If so, what are they? Use the following tables to document the existing dial plan: 3-18 Cisco Technical Solution Series: IP Telephony Solution Guide