VoIP (Voice Over IP). VoIP (Voice Over IP) VoIP Network Gateway functionality is required to adapt...

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VoIPVoIP(Voice Over IP)

Gateway functionality is required to adapt the PSTN transmission to IP (the Internet Protocol)

AnalogLocalLoop

Intranet/Internet

VoIP Network Network

Packet Switched

Logical ConnectionsG/WG/W G/WG/W

Voice Gateway A gateway provides:

Signaling - dial tone, call set-up etc. (H.323, MGCP, SS7) Conversion to IP, (often Ethernet, possibly ATM) Compression (G.711, G.723.1 etc.) Echo Cancellation Quality of Service (QOS)

PacketNetwork

Interface

PacketNetwork

Gateway Product

DigitalT1/E1

T3OC1/OC3

PhysicalInterfaces

Analogulawalawlinear

pulse dialing2W/4W

loop startground startgain control

ToneInterfaces

Tone GenerationDTMF

Call Progress Tone

Tone DetectionDTMFV.21

Call ProgressMF (R1, R2)

Modem Tone

DTMF ToneRelay

SignalingInterfaces

CASFXSFXO

E & MTransparent

CCSQ.931QSIG

Transparent

Voice/FaxProcessing

EchoCancellation

VoiceCoding

Voice Playout

Fax ModemV.21

V.27terV.29V.17V.33

Interfaces

CentralOffice

KeySystems

Voice/Fax Standards

Voice over IP H.323 SS7 MGCP SIP TCP/IP Tone detection Echo cancellation (G.165, G.168) Voice codecs V.x modems

Voice over Frame Relay FRF.11

Voice over ATM AAL2

Voice over Cable DOCSIS 1.1 MGCP

Fax over Packet T.37, T.38

Telephony

Interface

Protocol

Stacks

ATM Networks

Frame Relay Networks

IP Networks

H.323Gateway

PC w/H.323 Node

Frame RelayGateway

ATMGateway

Inter Operability Packet Network

Network ManagementInterface Functions

Gateway Product

H.323NetworkProtocolInterface

FRF.11NetworkProtocolInterface

ATMStandard In WorkProprietary Today

Address Translationand Parsing

Fax Relay/Advanced Local

Processing

Signaling TranslationCAS H.323/FRF.11/ATMCCS H.323/FRF.11/ATM

ITU-T Speech Coding Standards

Voice CODEC

th G.711G.726G.728G.729ABG.723

64 kbps

32 kbps

16 kbps

8 kbps5.3 kbps

Mean OpinionScore(MOS)

5.3 6.3 8 16 32 64

G.711 PCM

G.726 ADPCM

G.728 LD-CELP

G.729AB

G.723.1A

Subjective Voice Coder Quality

VoDSL (VoIP &VoATM)

VoATMAAL2

ADSL INTERLEAVED PATH

LifelinePOTS

AAL2AAL5

IPVoIP

LifelinePOTSDSL Client Access Network

ISP or Core

ADSL FAST PATH

TI’s Golden Port

Integrated software with simultaneous support for: Voice - Fax - V.90 Modem - Signaling

Network Requirements

Scalability - products typically range from 24/30 ports (T1/E1) to thousands of ports

Small Footprint - rack space in central offices and ISP POPs is expensive

Power Consumption - critical for both cost and heat Cost - cannot afford idle resources Simultaneous voice relay, fax relay, V.90 modem

termination Non-Blocking Manageable - accounting and operations

Network Efficient Utilization

Network Type Bandwidth Utilization Grade of Service

Telogy Software Provides Choice of low bit rate codecs Configurable voice packet sizes (10 ms to 80 ms) Efficient Voice Activity Detector (VAD) Fax demodulation/remodulation Ability to restrict max fax transmission rate, e.g., 2400, 4800, 9600 bps Sub-Channel Multiplexing - FRF.11

Universal Access

Recurring Cost Discrete Trunks

Capital Cost Idle Equipment

PacketNetwork

PSTN Replacement requires support for Voice, Fax and V.90 Modem

Channel Density

Multi-Instance - ability of software to support multiple modems in same DSP Old software base hard-coded for single channel operation;

difficult to migrate to multi-channel Software designed for multi-channel operation from its inception

results in a more robust product

Critical decisions on MIPS and memory vs. modem performance tradeoffs Skimping here will result in a poor performing solution

Hardware Architecture

Multi-processor

Real time call discrimination

Maximizes scalability

Eliminates the requirement for discrete trunks

Multi ProcessorT1/E1 Building Block

Ethernet(Internet)

CISC or RISC Processor Telephony Protocols Network Protocols Management Routing Billing

Digital Signal Processor(s) (DSP)

Voice Compression Tone Detection/Generation Echo Cancellation Silence Suppression Fax Modem V.90 Data Modem

RISC Processor Modem Control Processing

PSTN Trunks

Determines on a call by call basis if the calling “device” is a Human, Fax Machine, or a Modem Tone Detection Flag Detection Called number parsing

Dynamic Call Discrimination

CISC Ethernet(Internet)

480Miles

8 ms1 ms

60 Miles

960Miles

1,920Miles

Echo Cancellation

GatewayPBX

CO Switch with

echo canceller

Every 60 miles between the Gateway’s echo canceller and the reflecting hybrid requires 1 ms of echo tail

Telogy Software provides selectable tail length from 8 ms to 128 ms, G.165, G.168 compliant

Packet Loss Voice/Fax

Lost Packets Due to:•Network Congestion/Performance•Network Architecture•Improper Jitter Buffer Size•Software Not Designed for Peak Load

32 1 Playout

Buffer

GatewayProductPacket Network

Lost Lost

Telogy Voice Software Provides:•Lost packet compensation for all codecs•Lost packet statistics•Peak MIPS design philosophy

Telogy Fax Software Provides:•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)

Potential Causes of Packet Reordering:•Network Congestion/Performance•Network Architecture

GatewayProduct

Real-Time Fax Gateway Real-Time Fax Gateway

Emulates the Central Office and the remote fax machine (fax modem) Demodulates the fax transmission and extracts the fax data Encapsulates the fax data Transmits the fax data in packets Remodulates the fax data for transmission to the remote fax machine

PacketNetwork

64K bps

14.4 Kbps

64K bps

Success Factors for Fax over Packet Networks Success Factors for Fax over Packet Networks

PacketCompensation

Fax Interface Unit to Fax Interface

Unit CompatabilityDelay

Compensation

Network Call Stability

Fax to Fax Interface Unit Compatability

Analog Signal Quality

JitterCompensations

Fax LatencyFax Latency

OriginatingFTE FIU

DestinationFTE

Duration ofT.4 timer(per T.30)

Timeout occurswithout receiving a

reply and FTE startsretransmission oforiginal message.

FTE endstransmission and

starts T4 timer

Network

Retransmission from Originating FTE “collides”

with reply from Destination FTE

Technique To Technique To Keep Call AliveKeep Call Alive

Duration of T.4 timer(per T.30)

OriginatingFTE FIU FIU

DestinationFTE

NetworkFTE endstransmission and

starts T4 timerDelay

Message arrives overnetwork. FIU remodulatesmessage as it is received.

Before timeout at Originating FTE, FIU starts sending “preamble” fill signal in anticipation of receiving message over network.

Difference Between a Good Modem and aDifference Between a Good Modem and aGreat ModemGreat Modem

Key Algorithms - where some vendors cut corners Echo Canceller and Equalizer

Structure, speed and level of convergence, length Full vs. Reduced Complexity Viterbi decoder Handshaking sequence

Works reliably in channel impairment situations Full channel analysis

Smart optimization techniques

Network ManagementNetwork Management

Telogy Software Provides Quality statistics Supervisory statistics Online configuration Complete SNMP MIB for VOP

ChallengesQuality Measurement

Packet Loss Latency Jitter

Supervisory Measurement Call Accounting Call Type

Configuration Address Translation Signaling Mode Network Environment Parameters

Network Management Diagnostics Network Management Diagnostics

VOICE MON - Voice Packet Software MonitorPCM trace capabilityLoop back capabilitySignal level measurementsPlayout statisticsMemory dump facility

FAX MON - Fax Software MonitorReal-time fax traceAll significant eventsMillisecond accuracy on timestampingCompress format interpreted by PC software

SIG MON - Micro Signaling Trace MonitorReal-time trace capabilityControllable levels of tracingAll significant events including state changes, etc.Customer can route output to Monitoring System

V. MON - Modem MonitorReal-time trace capabilityConfiguration optionsStatisticsStatus

Software Scalability Software Scalability

What to Look For: Pre-integrated hardware and software scaling from One to Thousands of ports Optimized solutions and cost for all market areas Synchronized feature migration

Client ProductsTelogy Software

Client Suite

Low DensityMulti-Function

Access ProductsTelogy Software

Access Suite

Multi-ChannelMulti-Function

Infrastructure ProductsTelogy Software

Infrastructure Suite

High DensityBroad range of

capabilities

Intellectual PropertyIntellectual Property

It’s a Standards-Based World G.728, G.729, G.723.1, etc. V.90, V.34, etc.

Intellectual Property Critical Success Factor for Marketplace Success Now at forefront of Customer focus

Key Competitive Issue Affects product costs Liability

Patents 101

Telephones and Fax Machines connect directly with each other over time division multiplexed circuits

Traditional TelephonyTraditional Telephony

Lahore Karachi

Central OfficeCentral Office

Connections are managed by Central Office Switches and Enterprise PBXs Route calls onto digital trunks Provide billing information (Call Detail Records - CDRs) Provide management information (Alarms, Usage etc.)

CircuitSwitched

DigitalTrunks

AnalogLocalLoop

ModemsModems

Analog Modem calls are made in the same way as PSTN voice and fax calls

CircuitSwitched

DigitalTrunks

AnalogLocalLoop

Modems and the Internet/Intranet Modems and the Internet/Intranet

PC Client to WEB Server rather than Peer to Peer Many clients connecting through each POP

Digital access trunks required to be operationally economical

Remote Access Servers (RAS) An integration of Digital Modems and IP Router

PacketNetwork

RemoteAccess Server

WEBServer

Basics-Analog Voice to PCMBasics-Analog Voice to PCM

An analog voice signal is received

The Signal is converted to a Pulse Code Modulation(PCM) digital stream

10110101 11010011 11001001 00100100 00111100 10010011 11100001 00100100

Basics-PCM to FramesBasics-PCM to Frames

11010011 11001001 00100100 00111100 10010011 11100001 00100100 00111100

And Voice frames are created

10110101 11010011 11001001 00100100 00111100 10010011 11100001 00100100 00111100

The PCM stream is fed into the CODEC

10110101

Each Frame is 10 ms long (G.729a) and contains 10 bytes of “speech”

SummarySummary

Carrying Voice, Fax and Data over Packet networks provides the most bandwidth efficient method of integrating divergent technologies

While the challenges to this integration are substantial, the expanded market addressed by Telogy’s Golden Port make universal port implementations your best choice

VoIP (Voice Over IP). VoIP (Voice Over IP) VoIP Network Gateway functionality is required to adapt...

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