Director, Product Management Internet Telephony Expo The Essential Developer’s Toolkit for Designing Enterprise IP Telephony Debbie Greenstreet Director, Product Management Texas Instruments Internet Telephony Expo February 2003

Agenda Enterprise IP Telephony IP Telephony Architecture Key Functional Attributes Solution Components

Enterprise Network Telephony Evolution Server SME Gateway PBX Packet Network IP PBX LAN IP enabled PBX As mentioned earlier, corporate networks were one of the primary applications to benefit from VoIP technology. These solutions migrated from the access devices, or Small Medium Enterprise gateways to IP based solutions. IP based PBXs IP phones Allied Business market report predicts that the SME IP PBX hosted business will exceed $12.7 B by the end of 2007 and that over 50% of seats shipped will by IP by 2003. IP Centrex good market opportunities as well.

Enterprise Gateway Block Diagram Network Switch/Router WAN ENET PHY PBX Call Services T1/E1 Trunk LAN ENET PHY RISC FLASH SDRAM T1/E1 FRAMER T1/E1 Trunk DSP SRAM VoIP Functionality Network/PBX Functionality

Enterprise IP Phone Block Diagram User Interface Color Graphics Processor and Associated Logic Memory Interface SDRAM IP Phone Chipset LCD I/F Keypad Memory Intf Keypad I/F FLASH Audio I/F Voice Interface Spec available The reference design will be implemented as the TI IP Phone development and demonstration board. Customers can use this to develop their IP Phone application code to the APIs which we will provide. Customer application code will include things like the user interface (display, speed dials, keypad control), and all the PBX type functions (call hold, forwarding, etc…) USB I/F OR USB Interface Ethernet Interface Speaker Microphone Handset RJ11 Headset DEVICE HOST LAN RJ45 PC RJ45 Network Interface

VoIP Signal Processing Functional Components Fax Relay Fax Data Pump Fax Protocol Relay Interface T.30 Fax Voice SLIC PCM Interface Packet Voice Protocol Echo Canceller Tx Gain CONF VAD Network Driver Packet Interface Voice Codec CODEC Tone Gener- ation Voice Playout Rx Gain GSM Signaling Signaling Support Tone Detection Caller ID

VoIP RISC Software Functional Components CAS/CCS Signaling Call Control Supplementary Services H.323 Protocol SIP Protocol User Interface Unit Application Services Layer DSP Interface Ethernet Drivers IP TCP/UDP Telephony Hardware Abstraction Layer Hardware Abstraction Layer RTOS

Real-Time Fax Relay Packet Network FAX signal detection Demodulation of the fax transmission and extracts the fax data Remodulation of the fax data for transmission to the receiving fax machine FAX protocol processing eg, T.30 protocol Network Protocol Processing Packetizing/depacketizing T.38 UDP (TCP) Jitter control Error recovery Packet Network 64K bps 14.4 Kbps

Echo Canceller Functions Important Attributes Removal of echo from frame of PCM samples Doubletalk detection Acoustic Echo cancellation Important Attributes Convergence time (initial/updates) - time to train on the echo Convergence on narrowband signals (e.g., MF/DTMF tones) Suppress echo on DTMF digits Performance with high background noise - can cause instability and loss of echo cancellation

Interoperability - Telephony & Fax Challenges Gateway Product Digital T1/E1 T3 OC1/OC3 Physical Interfaces Analog ulaw alaw linear pulse dialing 2W/4W loop start ground start gain control phone PBX Central Office Key Systems modem fax Tone Interfaces Tone Generation DTMF Call Progress Tone Tone Detection DTMF V.21 Call Progress MF (R1, R2) Modem Tone DTMF Tone Relay Signaling Interfaces CAS FXS FXO E & M Transparent CCS Q.931 QSIG Voice/Fax Processing Echo Cancellation VAD Voice Coding Voice Playout Fax Modem V.21 V.27ter V.29 V.17 V.33 Ne t wo r k I n t e r f a c e Packet Network The breadth of interoperability issues are often overlooked when implementing a voice and fax over packet solution. A lot of telephony signaling standards as well as physical interfaces are involved in interface to the full range of telephony products. For a quality solution, and true interoperability, tone detection must be differentiated from the voice, and handled separately. Then, processing the subsequent signals (whether voice energy, modem tones, echo etc) has significant interoperability issues based on standards, network conditions and end station capabilities. Animations: 5 clicks to bring up groupings. 6th click - next slide ECO symbol back to main interoperability slide

Interoperability - Packet Network H.323 Gateway Gateway Product T e l e p h o n y I t r f a c Network Management Interface Functions IP Networks PC w/ H.323 Node P r o t o c l S t a k s Address Translation and Parsing Fax Relay/ Advanced Local Processing Signaling Translation CAS  H.323/FRF.11/ATM CCS  H.323/FRF.11/ATM H.323 Network Protocol Interface FRF.11 Network Protocol Interface ATM Standard In Work Proprietary Today Frame Relay Gateway Frame Relay Networks Of course, the network interface has a tremendous set of interoperability issues surrounding standards, network type, network conditions, configuration, addressing schemes, etc. Not only is the packet network type itself important with respect to support of interoperability and standards, but interoperability with respect to configurations and conditions within that network. Address translation between packet addressing and E.164 addresses, voice and fax encapsulation schemes, translation between telephony signaling and network signaling all have significant ramifications with respect to packet network interoperability. Animations: 3 clicks to bring up groupings. 4th click - next slide ECO symbol back to main interoperability slide ATM Gateway ATM Networks

Jitter (Variable Delay) Voice/Fax Playout Buffer Gateway Product Packet Network Variations in Packet Inter-arrival Rate Changes in network load Variations in routing paths Variable queuing delays Packet networks introduce another effect, not present in traditional TDM networks; variations in the rate which packets arrive. This jitter affects quality in both voice and fax solutions. The Golden Gateway solution provides a robust jitter buffer that provides dynamic sizing to accommodate varying network conditions. This buffer allows accumulation of enough packets to provide a constant cadence of packet playout to the user’s ear, or to the fax machine, avoiding voice and fax sample loss. Statistics on this buffer are provided to the gateway equipment for efficient use and flexible configuration. Not all solution on the market provide this important feature. Telogy can handle up to 300ms of jitter on fax calls, superior to most solutions. Animations: Groupings appear automatically. Click - next slide Hyperlink: Action button links to QOS Issues slide Key Features for Robust Playout Buffer: Adaptable playout buffer including: Programmable buffer size Dynamic buffer sizing Jitter buffer real-time statistics Fax - large jitter buffer to reduce the chance of lost packets

Packet Loss Voice/Fax Lost Packets Due to: Network congestion/performance Network architecture Improper jitter buffer size Software not designed for peak load Potential Causes of Packet Reordering: Network congestion/performance Network architecture Playout Buffer Packet Network 5 4 2 1 6 3 Lost Lost Another area that affects the quality of both voice and fax calls is network packet loss. Lost packets at the network level are due to network congestion, (significant activity and usage), and in some cases, insufficient or poor network architecture. Packet loss can occur at the voice/fax over packet gateway if a playout buffer to accommodate jitter is not employed, or is improperly sized. Packets may also be “lost” in a VoIP solution if the solution is not designed based on Peak MIPs performance of each of the functional elements. Telogy’s Golden Gateway is designed under a Peak MIPs assumption so that quality is not compromised under maximum operating conditions. The Golden Gateway recognizes when Packets are lost and provides such statistics for use by the gateway equipment. The playout buffer provides last packet re-play in the event of lost or missing packets. For fax systems, the control messages are transmitted three times to avoid missing packets at the receive side. Animations: 3 clicks to bring up groupings. 4th click - next slide ECO symbol back to main QOS slide Voice Software Must Provide: Lost packet compensation for all codecs Lost packet statistics Peak MIPS design philosophy Fax Software Must Provide: Control packet redundancy to correct for lost packets Advanced local processing to negate the effects of network problems Very high call completion rates (100% at 5%; 97% at 10)

VoIP Quality Monitoring What happens if it doesn’t sound good…. Telephony tools Support production lab testing LAN, packet network tools Don’t capture voice QOS problems Need passive monitoring tools Accurately estimate user perceived quality Measure live VoIP calls, not sample test calls Isolate and diagnose packet network quality problems Separate from signal processing quality problems. If the network is architected and managed correctly, VoIP with the appropriate QOS is feasible. Tools on the market that inject sample calls and measure. Also need to monitor the real stuff. ITU E model, G.107 R factor essentially translates to MOS score.

Other Features to Consider Security Often mentioned, but no common standard yet CableLabs including security for Voice over Cable IPSEC for signaling AES for voice packets Wireless LAN Natural progression from data network popularity Business office applications Consumer opportunities in Asia/Japan Concern by users of voice call integrity Concern by Law Enforcement – ie CALEA Concern by service providers for theft of services, DOS IETF IP sec 802.11b – 11Mbps 80211.g – 50Mbps and 11b compatible

Issues in Standards-Based Technologies New emerging markets and technology Need for interoperability among vendors, providers Standards bodies produce comprehensive specifications No way to avoid infringement Compliance requires use of third party IP Work-arounds/design-arounds not possible Infringement is easily identifiable If you are “in” a particular area you are infringing Website searches flag product offerings Potential liability is uncertain Validity/Invalidity of claimants’ IP Claimants may have IP but no pricing structure

Company Profiles Affect Risk and Response Three categories of companies at risk Technology providers Original equipment manufacturers End users Location in the “food chain” affects both risk and response IP Claim #1 Service Providers End Users Technology Providers OEM Manufacturers No Licensing, Indemnification $9/port Non-Payment can Result in Enjoinment IP Claim #n Example: Sum = $9/port

VoIP Product Development Checklist Time to Market Goal Product schedule Opportunity costs Internal Resources How many Expertise Product Differentiation Corporate expertise Market needs Risk Assessment Technology Intellectual property Scalability Feature growth

VoIP Toolkit – Silicon Ethernet Switch Digital Signal DSP RAM 802.11 Universal Serial Bus Reduced Instruction Set Computer Processor Digital Signal Analog Encoder Decoder Subscriber Line Interface Circuitry DSP RAM Ethernet Switch Synchronous Dynamic Random Access Memory ENET Media Control Physical Peripheral Component Interconnect 802.11 Internet Protocol Security (IPSEC)

VoIP Toolkit - Software Applications CAS/CCS Signaling Call Control Supplementary Services H.323 Protocol SIP Protocol User Interface Unit Application Services Layer DSP Interface Ethernet Drivers IP TCP/UDP Telephony Hardware Abstraction Layer Hardware Abstraction Layer RTOS Telephony Hardware DSP Software IP Network Hardware

VoIP Toolkit – Board Level Options Board level VoIP functionality with common interface, eg PCI, for insertion in larger system Basic level of core VoIP software often included IP phone reference design Benefits Board level design (hardware and software) complete Reduces hardware and software resources requirements ENET PHY RISC FLASH SDRAM T1/E1 FRAMER T1/E1 Trunk DSP SRAM

Toolkit Questions to Ask Silicon What hardware interfaces are required What level of functional integration makes sense Software What RTOS model makes sense Protocol source VoIP technology provider Third party expert Proprietary solution Call Control, Supp Services, etc How much is needed, uniqueness, expertise Applications model Feature differentiation Development/test tools

Your VoIP Product - Pulling It All Together Enterprise IP Telephony Requirements Variety of features, protocols – what is right for your product Market, cost goals Feature differentiation Evaluate Development Options Internal resources, expertise Off the shelf products Tools Available Hardware Chip sets, boards, reference designs Software RTOS Protocol stacks Call control, supplementary service Don’t forget test, quality of service, serviceability