Chapter 9: Connecting Branch Offices with Voice over Frame Relay, ATM, and IP 9-1 Copyright © 1998, Cisco Systems, Inc.

9-2CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Objectives Design, configure, integrate, and optimize voice in remote branch and regional offices by using technology that combines voice and data transmission over Frame Relay, ATM, and IP connections Appraise existing branch and regional office voice traffic, delay budget, and services, and choose the optimum transmission method for voice traffic: Frame Relay, ATM, or IP

9-3CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Objectives (cont.) Analyze existing voice hardware/software, and select which Cisco multiservice access device (2600, 3600 or MC3810) would best serve the needs Connect branch and regional offices with Voice over FR/ATM/IP Cover case studies of networks using VoFR, VoATM, and VoIP

9-4CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice versus Integrated Voice/Data Networks Voice NetworkIntegrated Voice/Data SignalingSignalingSignalingSignaling AddressingAddressingAddressingAddressing RoutingRoutingRoutingRouting Cost Effectiveness Cost EffectivenessCost Effectiveness Cost Effectiveness DelayDelay

Six-Step Network Design Process 9-5 Copyright © 1998, Cisco Systems, Inc.

9-6CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Six-Step Design Process 1. Current network audit 2. Network objectives 3. Technologies and services review 4. Technical guidelines 5. Capacity planning 6. Financial analysis

9-7CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 1: Current Network Audit Existing equipment Operating costs Capabilities Facility costs Upcoming projects Service quality Traffic study

9-8CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 2: Set Network Objectives Identify: Dominant traffic type Required voice quality Performance Cost

9-9CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 3: Technologies and Services Review Voice over Frame Relay Voice over ATM Voice over IP

9-10CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice over Data Summary The Best Technology Fit Frame Relay ATM IP

9-11CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 4: Technical Guidelines Voice quality guidelines Voice delay guidelines

9-12CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice Quality Factors Coding Compression Multiple conversions Delay/delay variation Line quality

9-13CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice Compression Compression Type Data Rate G.711PCM 64 kbps 32, 24, 16 kbps G.726ADPCM 8 kbps G.729CSA-CELP 16 kbps G.728LD CELP

9-14CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Compression Method MOS Score Delay (ms) PCM (G.711) K ADPCM (G.726) K LD CELP (G.728) 8K CSA-CELP (G.729) K CSA-CELP (G.729a) 10 Voice Quality Guidelines 3–

9-15CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice Quality Guidelines kbps Subjective Quality (MOS) Hybrid Coders (LD CELP and CSA-CELP) Vocoders (Older Technology) Wave Form Coders (ADPCM) ScoreQuality Description of Impairment 54321ExcellentGoodFairPoorBadImperceptible Just Perceptible, Not Annoying Perceptible and Slightly Annoying Annoying but Not Objectionable Very Annoying and Objectionable Source: A.M. Kondoz, Digital Speech Coding for Low Bit-Rate Communications Systems, 1995

Voice Delay: Calculating the Delay Budget 9-16 Copyright © 1998, Cisco Systems, Inc.

9-17CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Voice Delay Guidelines One-Way Delay (ms) Description 0–150 Acceptable for most user applications 150–400 Acceptable provided that administrations are aware of the transmission time impact on the transmission quality of user applications 400+ Unacceptable for general network planning purposes; however, it is recognized that in some exceptional cases this limit will be exceeded ITUs G.114 Recommendation

9-18CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Fixed Delay Components Propagationsix microseconds per kilometer Serialization Processing Coding/compression/decompression/decoding Packetization Processing Delay Propagation Delay Serialization Delay Buffer to Serial Link

9-19CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Variable Delay Components Queuing delay Dejitter buffers Variable packet sizes Dejitter Buffer Queuing Delay

9-20CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Calculate Delay Budget Propagation Delay32 ms Coder Delay 25 ms Serialization Delay 3 ms Dejitter Buffer 50 ms Queuing Delay 6 ms Los Angeles Munich (Private Line Network) Total 110 ms Dejitter Buffer 50 ms 32 ms Network Delay (e.g., Public Frame Relay Svc) Serialization Delay 64-kbps Trunk 3 ms 6 ms Queuing Delay 64-kbps Trunk 5 ms Packetization DelayIncluded in Coder Delay Coder Delay G.729 (5 ms Look-Ahead) Propagation Delay (Private Lines) Fixed Delay Variable Delay Coder Delay G.729 (10 ms per Frame) 20 ms

9-21CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Calculate Delay Budget Multiple Conversions Delay #2 Delay #1 Site A Site B Site C Private Line Network Fixed Delay Variable Delay DELAY #1 Coder Delay G ms Packetization Delay (Included in Coder Delay) (Included in Coder Delay) Queuing Delay 64-kbps Trunk6 ms Serialization Delay 64-kbps Trunk3 ms Propagation Delay (Private Lines)32 ms Dejitter Buffer50 ms Tandem Switch Tandem Switch Delay #1 Total110 ms

9-22CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Calculate Delay Budget Multiple Conversions (cont.) Delay #2 Delay #1 Site A Site B Site C Private Line Network Fixed Delay Variable Delay DELAY #1 Total110 ms DELAY #2 Coder Delay G ms Packetization Delay (Included in Coder Delay) (Included in Coder Delay) Queuing Delay 2-mbps Trunk0.2 ms Serialization Delay 2-mbps Trunk0.1 ms Propagation Delay (Private Lines)5 ms Dejitter Buffer50 ms Delay #2 Total80 ms Total Delay190 ms

9-23CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Technical Guidelines Summary Balance: voice quality, delay, and bandwidth Determine acceptable delay and delay variation thresholds Calculate delay for the chosen model Avoid tandem (multiple) conversions

9-24CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 5: Capacity Planning Line/trunk provisioning Bandwidth provisioning

9-25CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. ProvisioningTrunking Determine traffic volume and flow Calculate required number of trunks Grade of service PBX ? ?? ?

9-26CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. ProvisioningBandwidth Goal = desired voice quality + grade of service + cost effectiveness PBX ?

9-27CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Step 6: Financial Analysis Cost/benefit analysis Financial justification Return on investment

Case Studies: Voice over Frame Relay, ATM, and IP 9-28 Copyright © 1998, Cisco Systems, Inc.

9-29CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Global Firm Headquarters (30–50 People) PBX 5 Regional Offices (8–15 People) ISDN (384 kbps) PBX TDM MUX TDM MUX TDM MUX Private Lines Original Network Design Private Lines TDM MUX

9-30CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Global Firm PBX Network Redesign TDM MUX ATM Backbone

9-31CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Functional Highlights Silence Suppression SpeechSilenceSpeech No Cells CellsCells Voice Activity Detection

9-32CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Functional Highlights Optimal Bandwidth Utilization Cell Switching Q Feedback Set Congestion Indicators Adjust Admission Rate Monitor Congestion Indicators Traffic Management LAN SNA Voice Video PBX FEP

9-33CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Financial Analysis Payback 4 months Yearly savings $3.5M Capital outlay $1.2M Capital Outlay $1.0M $500K Month Payback

9-34CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 1: Summary 30 percent reduction in annual expenses Voice quality maintained Increased network availability Simplified management Optional tandem replacement

9-35CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Pan-European Firm Munich Brussels Milan Paris London Dublin Stockholm PSTN Madrid Geneva Frame Relay Service Case 2A

9-36CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Pan-European Firm Regional Offices 40–70 People Original Network Design Frame Relay Service VPN

9-37CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Redesigned Topology Munich Brussels Milan Paris London Dublin Stockholm PSTN Madrid Geneva

9-38CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Regional Offices Network Redesign Frame Relay Service VPN Cisco MC3810

9-39CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Headquarters VPN Network Redesign Frame Relay Service Cisco MC3800

9-40CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Functional Highlights Voice prioritization within a single PVC (bundled DLCI) Tandem switching ATM service ready Multiflex trunk

9-41CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Financial Analysis Payback 7.5 months Yearly savings $230,000 Capital outlay $128,000 Month $50K $150K Capital Outlay Payback $100K

9-42CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 2: Summary Annual savings over $230,000 Voice quality maintained using voice priority Voice decompression/ recompression cycle avoided

9-43CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Multinational Firm Frankfurt London San Jose, CA Chicago New York Tokyo Hong Kong Milan PSTN Case 3B

9-44CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Multinational Firm Seven Offices 15–45 People Original Network Design VPN Cisco C3600

9-45CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Multinational Firm VPN Network Redesign Cisco 3600

9-46CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Redesigned Topology Frankfurt London San Jose, CA Chicago New York Tokyo Hong Kong Milan PSTN

9-47CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Functional Highlights Extend the routed network architecture Only 9 kbps per call Migration path to Frame Relay Future interoperability with H.323 applications

9-48CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Functional Highlights Dial Plan

9-49CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Financial Analysis Payback 8 months Yearly savings $173,000 Capital outlay $110,000 Month $50K $150K Capital Outlay Payback $100K

9-50CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Case 3: Summary Annual savings over $173,000 Management simplified using Java-based manager Voice decompression/ recompression cycle avoided

9-51CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Summary Design, configure, integrate, and optimize voice in remote branch and regional offices by using technology that combines voice and data transmission over Frame Relay, ATM, and IP connections Appraise existing branch and regional office voice traffic, delay budget, and services, and choose the optimum transmission method for voice traffic: Frame Relay, ATM, or IP

9-52CVOICEConnecting Branch Offices with Voice over Frame Relay, ATM, and IP Copyright © 1998, Cisco Systems, Inc. Summary (cont.) Analyze existing voice hardware/software, and select which Cisco multiservice access device (2600, 3600 or MC3810) would best serve the needs Recommend ways to connect branch and regional offices with Voice over FR/ATM/IP Cover case studies of networks using VoFR, VoATM, and VoIP