This application note describes example implementation voice over Inte

The Datasheet Archive - 100 Million Datasheets from 7500 Manufacturers.

This application note describes example implementation voice over Inte

Datasheet Thumbnail

Top Searches for this datasheet

Implementing Voice Over Internet Protocol
This application note describes example implementation voice over Internet protocol (VOIP) functionality using Altera® high-density APEXdevices intellectual property (IP) functions from Altera Megafunction Partners Program (AMPP MegaCore® program. This application note discusses following topics: VOIP fundamentals Creating system-on-a-programmable-chip (SOPC) solution with APEX devices functions that used VOIP system
VOIP Fundamentals
Altera Corporation
A-AN-128-01.1
VOIP system captures, packetizes, transports telephone conversations (voice data) over network originally designed transport computer-generated data data network). This approach transporting voice traffic solves long-term cost issues organizations that existing voice traffic transport systems, called circuit-switched networks. implementing VOIP transporting voice traffic over Internet, circuit-switched networks their associated maintenance costs replaced less expensive solution.
Comparing Circuit-Switched Networks Data Networks
topology behavior circuit-switched networks data networks significantly different. Voice traffic carried over system originally designed data creates technical challenges that must addressed ensure high quality service (QoS). refers ability network satisfy voice traffic service requirements. Circuit-switched networks sacrifice maintenance costs high QoS, data networks sacrifice bandwidth efficiency. Circuit-switched networks have high because they dedicate bandwidth resources each individual call duration that call. However, dedicating permanent resources individual call creates significant cost disadvantages circuit-switched networks. Additionally, because most voice conversation consists "pauses" where voice transmission takes place, circuit-switched networks cannot utilize available bandwidth efficiently, resulting cost disadvantage when compared data networks.
128: Implementing Voice Over Internet Protocol
Unlike circuit-switched networks, data networks dedicate permanent resources individual call between locations. Instead, data prepared network transport attaching classification information packet header, which attached payload. data network uses path network that optimizes utilization available bandwidth. Figure illustrates voice data prepared traveling over data network. Figure Packetization Voice Traffic
Voice Data
Capture Voice Data
101101011101101011101101
1001010111011101011
10110101110110110
Packetization Voice Data
10110101
11011010
11101101
10010101
11011101
10110101
11011011
Packets from Other Sources
Internet
Absence Industry Standards
Currently, very industry standards exist VOIP products. System implementations vary from complete software architectures complete hardware architectures combinations both. Because VOIP environment lacks defined standards, specifying fabricating ASIC device using particular standard introduces significant risk standards evolve. Altera programmable logic devices (PLDs) VOIP-enabled products ideal because they reconfigured provide fast time-to-market.
Altera VOIP
illustrate advantages designing VOIP system using Altera products, this application note details architecture VOIP gateway. VOIP gateway architecture example utilize APEX devices functions that reduce system costs simplify development cycle.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Intellectual Property
Altera provides range functions that give designer access vast array applications commonly used within VOIP applications. Parameterizable, shrink-wrapped solutions allow designer concentrate system architecture optimization. VOIP system example uses more than different functions, which obtained from AMPP MegaCore programs Altera site
APEX Device Family
Altera APEX family high-density PLDs offers number advantages developing VOIP systems. APEX devices reconfigured meet future standards, even when deployed field. Content addressable memory (CAM) implemented on-chip perform quick searches routing information. APEX device family also supports gunning transceiver logic plus (GTL+) standard, which used implement stringent requirements TimeDivision Multiplexed (TDM) bus.
Quartus Software
Quartussoftware provides world-class SOPC development environment also incorporates best-in-class third-party tool flows with NativeLinkintegration achieve best design possible APEX devices. Additionally, Quartus software features SignalTaplogic analyzer, SOPC debugging tool. more information SignalTap logic analyzer, SignalTap Embedded Logic Analyzer Megafunction Data Sheet.
SOPC Solution Example VOIP
VOIP gateway example network system provided this section highlights functions APEX device features that provide implementation-level benefits VOIP developers. VOIP gateway network system consists shelf, which contains three lines types cards, each featuring APEX device. Figure shows overview example VOIP gateway network system.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Figure VOIP Network System Overview
Shelf
Digital Access Card
POTS Internet Digital Access Card
Hand
POTS
Hand
Control Packet
Hand
first type card VOIP network interfaces with Internet infrastructure referred digital access card (DAC). second type card manages interface between telephone hardware routing network. Because much functionality based standard telephony requirements, referred "plain telephone service" (POTS) card. Additional POTS cards added system meet availability performance needs service. Telephones connected externally cards with standard telephone wire that connects POTS card. Each POTS card handle phone lines, system scaled meet specific needs adding POTS cards board. cards interface with Internet line. Each card carry four lines. this example, lines connect gateway Internet frame relay network; however, other types networks also connected similar shelf.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Three separate buses allow control data information passed between cards system. carries unpacketized voice data between cards system. Packet carries voice traffic ethernet packets between cards, Control manages communication between POTS cards.
POTS Card
POTS card similar other standard cards used telephone networking systems today. POTS card example used this document, possible functionality available form functions been implemented within APEX device demonstrate functionality SOPC. Figure illustrates role functions APEX device within POTS card. Figure POTS Card Functional Diagram
POTS Card APEX Device SLIC CODEC Telephone Fast Fourier Transform Function SLIC CODEC Telephone Tone Generation Function GainGen Function
Switch Function
Phones
Processor Function
Processor
Ethernet Function
Control
SDRAM Controller Function
SDRAM
Flash Boot
POTS card's primary purpose route calls from attached telephones. does perform packetization. subscriber line interface circuit (SLIC) standard coder/decoder (CODEC) convert voice signal digital data compress pulse-code modulation (PCM) signal.
Altera Corporation
128: Implementing Voice Over Internet Protocol
following section describes detail role each function APEX EP20K200EFC672-1 device VOIP system example. This particular APEX device chosen because offers right combination logic capacity memory. This section describes following functions POTS card: Gain Generation Function Switch Function Tone Generation Function Processor Function Ethernet Media Access Control (MAC) Function Tone Detection Function Memory Functions
Gain Generation Function
When digitized voice data multiplexed together off-chip, Gain Generation function receives voice data adjusts gain appropriate level, depending final destination voice signal. voice data sent over Internet, decibel adjustment necessary. call sent within gateway, standard 6-dB loss added signal. Regardless call's final destination number signals bus, function easily scale appropriate gain level with correct processor input.
Switch Function
Once gain properly adjusted, Time-Division Multiplexed (TDM) Switch function receives incoming data maps appropriate destination. Switch function samples incoming multiplexed signal sends data over according instructions provided microprocessor. Switch function reduces constant delay signal. Also, variable frame width/bit level switching feature allows greater control between channels. number input streams, output streams, bits time slot, time slots frame modified meet specific system needs. Because many POTS cards introduce contention bus, collision detection enabled with GTL+ interface, available directly APEX device. collision detected, every card system notified Ethernet control bus.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Tone Generation Function
Tone Generation function provides audible tones informing user operation mode current call. selected tones turned off, simultaneously supplied Switch function (the Tone Generation function does have input). Switch function selects appropriate tone based data receives from Processor bus. Switch function sends this tone signal back handset. example, when call been routed successfully waiting response, processor POTS card tells Switch select channel that generates "ringing" sound. other connection already use, processor instructs Switch function select channel that generates "busy" signal. Tone Generation function from AMPP partner NComm, Inc. MegaWizard® Plug-In, which allows user select only tone parameters required. Using MegaWizard interface also ensures optimum embedded system block (ESB) usage calculating least number samples required generate tone sequence. Tone Generation function also supports optional gain control, Mu-law, Alaw encoding. resource utilization summary this example reflects instantiation NComm function, which includes dial tone, ring back tones, busy signal.
Processor Function
Processor function modeled 32-bit MIPS-basedinstruction with R3000 class architecture. capable operating Altera APEX device executes instructions over five-stage pipeline. transactions within Processor interfaces occur positive edge processor clock require two-phase clocks implementation. result, Processor function does on-chip phase-locked loops (PLLs). Processor function selected this example LX-4180 from Lexra. Processor function receives input from incoming call determines where route signal based phone number dialed (outgoing) address (incoming). also supplies control information peripheral functions, including Tone Generation function, Fast Fourier Transform (FFT) function, SDRAM Controller functions. Processor function POTS card only accesses Control Ethernet function. does have access Packet bus, which reserved communication between cards.
Altera Corporation
128: Implementing Voice Over Internet Protocol
32-bit co-processor operations supported, including moves from co-processor's general registers control registers. co-processor loads stores based co-processor condition flags. co-processor operations execute single clock cycle without pipeline stalls. Processor function also features configurable cache sizes separate data instruction memory spaces, which implemented using ESBs APEX device.
Ethernet Function
Ethernet function transmits receives signals Control bus. function implements media access control (MAC) complies with IEEE standard 802.3. Ethernet function selected this example from CoreEl Microsystems. This function supports both Reduced Media Independent Interface (RMII) Media Independent Interface (MII) physical ethernet layer, which implemented off-chip. instantiation this example uses interface supports 16-bit host interface.
Tone Detection Function
Tone Detection block function from Altera AMPP partners; custom piece logic. Tone Detection block detects tones generated handsets correlates these tones numerical address that represents destination call.
Memory Functions
There three types memory functions within POTS card example: Flash ROM, SDRAM, CAM. Flash stores software needed initialize hardware. SDRAM Controller provides handshaking protocol processor function standard interface SDRAM. This example system requires Mbytes off-chip SDRAM. SDRAM Controller allows programmable constrained timing, well bank management cascading. SDRAM Controller also supports eight banks memory with Gbits memory space maximum speed within APEX device single data rate mode. special interface connecting 32-bit MIPS-based processor SDRAM Controller required complete integration these functions.
Altera Corporation
128: Implementing Voice Over Internet Protocol
CAM, which implemented within APEX device, performs quick database searches routing information. POTS card, stores telephone numbers corresponding specific addresses, allowing processor execute faster searches.
Digital Access Card
card, shown Figure prepares data travel over Internet, unpacks data received from Internet lines, converts back voice format used shelf. addition Ethernet control Switch buses, also uses Ethernet packet which routes packetized voice information between cards shelf. Figure Card Block Diagram
Card
APEX Device Framer Function HDLC Function Echo Canceller Custom Function Switch Function GTL+
Frame Relay Network Trunks
Framer Function
HDLC Function
Packet-Voice Conversion Voice Compression (Custom Function)
Processor Function
Processor
Ethernet Function
Packet
SDRAM Controller Function
Ethernet Function
Control
SDRAM
Flash Boot
card support lines. card also access three buses shelf: Switch bus, Control (Ethernet-based) Packet (Ethernet-based). APEX device selected card, based resource requirements, EP20K400EFC672-1.
Altera Corporation
128: Implementing Voice Over Internet Protocol
line interface unit (LIU) off-chip, analog device that connects APEX device packet network. this example, frame relay protocol packet network. When APEX device receives synchronous signal, packets streamed through Framer function detection. following section describes detail role each function card VOIP system example. This section describes following functions: Framer Function High-Level Data Link Controller (HDLC) Function Switch Function Processor Function Ethernet Function Memory Functions
Framer Function
Framer function identifies every 193rd data framing bit, with first bits data carrying addresses packetized voice information. This function partitions stream processing using HDLC function. Each Framer function handles line with four lines board. Framer function selected this example from CoreEl Microsystems, Altera AMPP partner. When transmitting, function clocks data serial form puts frame format serial stream.
HDLC Function
HDLC function adds removes protocol information during packet transit. When packet arrives from frame relay network, longer needs communication protocol bits required network transit. Therefore, these protocol bits stripped, leaving packet with local routing information. When leaving system enter network, packet needs these bits added addressing information. HDLC function used this example from Premier AMPP partner Innocor Ltd. HDLC function high-performance module bit-oriented data transmission. function designed maximize speed while reducing resource consumption APEX device. Available control features include 16-bit cycle redundancy checker (CRC), flag insertion/deletion, zero insertion/detection, abort generation/detention. design fully synchronous operate MHz.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Switch Function
Once gain properly adjusted, Switch function receives incoming data maps appropriate destination. Switch function samples incoming multiplexed signal sends data over according instructions provided microprocessor. Switch function reduces constant delay signal. Also, variable frame width/bit level switching feature allows greater control between channels. number input streams, output streams, bits time slot, time slots frame modified meet specific system needs. Because many cards introduce contention bus, collision detection enabled with GTL+ interface, available directly APEX device. collision detected, every card system notified Ethernet control bus.
Processor Function
Processor function modeled 32-bit MIPS-based instruction with R3000 class architecture. capable operating Altera APEX device executes instructions over five-stage pipeline. transactions within Processor interfaces occur positive edge processor clock require two-phase clocks implementation. result, Processor function uses on-chip PLLs. Processor function selected this example LX-4180 from AMPP partner Lexra. Processor function receives packetized information from frame relay network determines where route signal based phone number dialed (outgoing) address (incoming). Processor function also supplies control information peripheral functions including Tone Generation function, signal detection logic, SDRAM Controller functions. Processor function does have access Packet bus, which reserved communication between cards. system supports 32-bit co-processor operations, including moves from co-processor's general registers control registers. co-processor loads stores based co-processor condition flags. co-processor operations execute single clock cycle without pipeline stalls. Processor function also features configurable cache sizes separate data instruction memory spaces, which implemented using ESBs APEX device.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Ethernet Function
card Ethernet functions. function provides Control other function provides Packet bus. function implements complies with IEEE standard 802.3. Ethernet function selected this example from CoreEl Microsystems. This function supports both RMII interfaces physical ethernet layer, which implemented off-chip. instantiation this example uses interface supports 16bit host interface.
Memory Functions
card example uses three types memory functions: Flash ROM, SDRAM, CAM. Flash stores software needed initialize hardware. SDRAM Controller provides handshaking protocol processor standard interface SDRAM. This example system requires Mbytes off-chip SDRAM. SDRAM Controller allows programmable constrained timing, well bank management cascading. SDRAM Controller also supports eight banks memory with Gbits memory space maximum speed APEX device single data rate mode. special interface 32-bit MIPS-based processor SDRAM Controller required complete integration these functions. CAM, which implemented within APEX device, performs quick database searches routing information. card, stores telephone numbers corresponding specific addresses, allowing processor execute faster searches.
Reconfigurability
fixed solution requires separate board each network accommodate packet protocols specific each system. VOIP system described this document, programmable logic allows designer replace HDLC function with other network interface functions. example, same cards could used same shelf replacing HDLC function with asynchronous transfer mode (ATM) adaptation layer segmentation reassembly (SAR) function same board connect Anetwork. This approach only cuts costs board development prototyping, also eliminates debugging problems associated with multiple board solution.
Altera Corporation
128: Implementing Voice Over Internet Protocol
Conclusion
networks larger maintenance costs continue rise, VOIP network voice communication becomes more attractive. Because VOIP major step direction voice communication, many solutions have been implemented attempt best serve marketplace. Altera provides flexible VOIP network system solution using APEX device combination that meet changing needs consumers industry standards evolve systems improve. Altera APEX device functions enable designers retain flexibility without sacrificing functionality provided fixed solution. APEX device comes equipped with advanced memory features providing designers with more options within design environment. Altera portfolio reduces time-to-market with substantial advanced functions. Altera functions also easily adjust designer's specific needs work seamlessly with Quartus design integration tool. Altera's APEX device functions provide powerful flexible solution VOIP network system.
References
more information Altera functions APEX devices, refer documents listed below. documents available through Altera Megafunction Partners Program (AMPP) through Altera site http://www. altera.com. Compiler MegaCore Function User Guide (High-Speed Adaptive Filter Megafunction) (Fast Fourier Transform MegaCore Function) Operating Requirements Altera Devices Data Sheet Altera Device Package Information Data Sheet Using Standards Quartus Software White Paper Quartus Programmable Logic Development System Software Data Sheet (Using Selectable Standards Altera Devices) (Using Timing Analysis Quartus Software) (Implementing High-Speed Search Applications with APEX CAM)
Revision History
Altera Corporation
This revision removes references Echo Canceller function.
128: Implementing Voice Over Internet Protocol
Innovation Drive Jose, 95134 (408) 544-7000 http://www.altera.com Applications Hotline: (800) 800-EPLD Customer Marketing: (408) 544-7104 Literature Services: lit_req@altera.com
Altera, AMPP, APEX, APEX 20K, MegaCore, MegaWizard, NativeLink, Quartus, SignalTap trademarks and/or service marks Altera Corporation United States other countries. MIPS-based trademark MIPS technologies, Inc. Altera products protected under numerous U.S. foreign patents pending applications, maskwork rights, copyrights. Altera warrants performance semiconductor products current specifications accordance with Altera's standard warranty, reserves right make changes products services time without notice. Altera assumes responsibility liabilityarising application information, roduct, service described hereinexcept sexpressly agreed toinwriting Altera Corporation. lteracustomers advisedtoobtain orders products services. Copyright 2000 Altera Corporation. rights reserved.
Printed Recycled Paper.
Altera Corporation

This application note describes example implementation voice over Inte

Top Searches for this datasheet

Other recent searches