2. VoIP
(Voice Over IP)

3. VoIP Network
Gateway functionality is required to adapt the PSTN transmission to IP (the Internet Protocol)
Intranet/Internet
Packet Switched
Logical Connections
G/W
G/W
Now to connect these TDM circuits over an IP network, gateway functionality is required (gatewaying telephony and packet netowrks together). This could be any type of packet network.
Analog
Local
Loop
Analog
Local
Loop
by Naveed Akhtar Bokhari

4. Voice Gateway A gateway provides: Packet Network
Signaling - dial tone, call set-up etc. (H.323, MGCP, SS7)
Conversion to IP, (often Ethernet, possibly ATM)
Compression (G.711, G etc.)
Echo Cancellation
Quality of Service (QOS)
Let’s look at what a voice gateway does in terms of connecting PSTN traffic to an IP network. In addition to simply connecting the signals, it must handle the conversion of the signaling information that details the call setup, connection and tear down information. It must translate the information to IP protocols and the gateway must perform key processing on the voice samples themselves to assure proper reception at the telephony endpoint (i.e. compression, echo cancellation, etc.)
Bullets:
Conversion to packet network(IP , frame relay, ATM)
Encoding/Compression G.729AB
Echo G.165, G168
Change cloud to packet netowrsk
Packet
Network
by Naveed Akhtar Bokhari

5. alaw linear pulse dialing DTMF Call Progress Tone
Interfaces
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
N e t w o 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
by Naveed Akhtar Bokhari

6. Voice/Fax Standards Voice over IP Voice over Frame Relay
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
by Naveed Akhtar Bokhari

7. Inter Operability 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
by Naveed Akhtar Bokhari

8. ITU-T Speech Coding Standards
64 kbps
32 kbps
16 kbps
8 kbps
5.3 kbps

9. Subjective Voice Coder Quality
Mean
Opinion
Score (MOS)
The voice compression scheme used in the voice over packet solution affects quality in several ways. First, the MOS score varies amongst the variety of codecs; some closer to toll quality than others. Those at lower bit rates require less network bandwidth which can save on network resources, however the tradeoff comes in accumulation delay. For example codec has 5.3 and 6.3 kbps compression rates but consumes 30ms per frame for sample accumulation. In addition, it is very important for voice over packet implementers to listen to the software solution for voice compressions, especially in the presence of multiple voice channels as well as in conjunction with active fax calls. While compression schemes may pass ITU standard vectors, the performance may degrade when integrated with the rest of the voice over packet software solution. The use of Comfort Noise Generation in conjunction with compression is important for overall user quality perception. If silence is detected by the user between voice energy, it may be assumed that the connection has been terminated (based on our experience with traditional PSTN).
Animations:
No animations.
click - next slide ECO symbol back to main QOS slide
Kpbs
by Naveed Akhtar Bokhari

10. VoDSL (VoIP &VoATM) ISP or Core Access Network DSL Client VoATM AAL2
ADSL INTERLEAVED PATH
PLVT
VoIP
Lifeline
POTS
PPP
AAL5
DSL Client
Access Network
ISP or Core
ADSL FAST PATH

11. TI’s Golden Port Integrated software with simultaneous support for:
Voice - Fax - V.90 Modem - Signaling
So, what is the ideal solution here. That would be to have a single piece of equipment that not only integrates the gateway functions for voice, fax and data modem, as well the corresponding telephony signaling, but allows the conversion to be performed dynamically on a call by call basis. This solution not only optimally handles the types of incoming telephony traffic but reduces the additional equipment costs incurred by having discrete trunks and idle equipment.
by Naveed Akhtar Bokhari

12. 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
What are the requirements for this single equipment. Read list.
Non blocking - if resources are not properly allocated, a call will be blocked - so it’s like having a T1 but only being able to have 22 (not 24 calls).
by Naveed Akhtar Bokhari

13. 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
Depending on the network type employed bandwidth utilization can have an impact on end user costs. Providing a solution that can adapt to the varying requirements, via selectable codecs, fax demod, remod, etc. are important for an efficient, cost effective voice/fax over packet solution. Some solutions cannot reconfigure to accommodate changes in network utilization. VAD is an important aspect in reducing network bandwidth; it is important to assure that the solution includes it.
Animations:
2 clicks to bring up groupings.
3rd click - next slide
by Naveed Akhtar Bokhari

14. Universal Access PSTN Replacement requires support for Voice,
Fax and V.90 Modem
Capital Cost
Idle Equipment
Recurring Cost
Discrete Trunks
What needs to happen in order to provide the functionality we just described for voice and fax gateways and remote access servers -- in a single piece of equipment? To replace the PSTN with an IP network, and to support all modes of telephony data, we essentially have to perform the functions just described in the voice and fax gateways and remote access servers, there are several challenges involved with this. If we were to do thiws with separate pieces of equipment, we wouod face several challenges. We have recurring costs of dscrete digital trunks between the central office and the gateway equipment un-used -- that is, one trunk for each type of data. Additionally, we have capital costs that reffffflect un-used circuitry b/c theequipment is not fully utilized for each type of data.
Termination -- data comes out of a network in a different format
Packet
Network
by Naveed Akhtar Bokhari

15. 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
by Naveed Akhtar Bokhari

16. Hardware Architecture
Multi-processor
Maximizes scalability
Real time call discrimination
Eliminates the requirement for discrete trunks
To meet these requirements the following features are required. Utilizing a multi-processor architecture maximizes the scaleability of the equipment. A single T1, up to many can be handled in a given architecture. The equipment must be able to identify the type of call received from the incoming digital trunk such that each trunk can support a heterogeneous mix of data. This reduces the need, and resulting overhead of separate trunks for each telephony data type. Correspondingly, the processor resources must be able to be dynamically allocated to handle one of each type of call. This allows the minimum number of processing resources to be used, which in turn reduces power consumption, heat dissipation, keeps the footprint of the processing as small as possible, and reduces overall cost.
by Naveed Akhtar Bokhari

17. Multi Processor T1/E1 Building Block
Digital Signal Processor(s) (DSP)
Voice Compression
Tone Detection/Generation
Echo Cancellation
Silence Suppression
Fax Modem
V.90 Data Modem
DSP
RISC Processor
Modem Control Processing
PSTN Trunks
Ethernet
(Internet)
Read List
RISC processor optiizes soloution to get as many channels as possible
Yiou can combine ISC and CISC as one processor.
4 RISCs going into 1 CISC
CISC or RISC Processor
Telephony Protocols
Network Protocols
Management
Routing
Billing
by Naveed Akhtar Bokhari

18. Dynamic Call Discrimination
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
DSP
DSP
RISC
CISC
Ethernet
(Internet)
DSP
DSP
by Naveed Akhtar Bokhari

19. Echo Cancellation
1,920
Miles
32 ms
Every 60 miles between the Gateway’s echo canceller and the reflecting hybrid requires 1 ms of echo tail
16 ms
960
Miles
480
Miles
8 ms
1 ms
60 Miles
Gateway
PBX
CO Switch
with
echo canceller
The echo cancellation takes place at the Gateway as part of the digital signal processing. The echo tail refers to the amount of time the channel is sampled for echo cancellation. A software solution that offers a selectable tail length, affords the equipment manufacturer flexibility in deployment of its voice over packet products. Utilizing a tail that is longer than necessary can waste DSP resources, while utilizing a tail that is too short will result in an incomplete echo cancellation system. ITU standards dictate echo cancellation quality. Telogy’s Golden Gateway solution exceeds the G.165 standards.
Network delay has nothing to do with the size of the echo canceller. It has everything to do with needing the echo canceller.
Insert “men” slide re: echo after this one. Slide for each application re: where the echo canceller resides
Telogy Software provides selectable tail length from 8 ms to 128 ms, G.165, G.168 compliant
by Naveed Akhtar Bokhari

20. 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
Gateway Product
Gateway Product
Packet Network
Playout Buffer 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
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)
by Naveed Akhtar Bokhari

21. 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
Similar to the voice gateway, the fax gateway has to perform conversions fax relay solutions need to demodulate the fax transmission and insert fax data into packets. Fax signaling protocol must also be translated between the fax terminating equipment and the gateway and transported across the packet network. Do the same conversely on the other end.
Packet
Network
64K bps
14.4 Kbps
by Naveed Akhtar Bokhari

22. Success Factors for Fax over Packet Networks

23. FTE ends transmission and starts T4 timer
Fax Latency
Originating
FTE
Destination
FTE
FIU
FIU
FTE ends transmission and starts T4 timer
Network
Delay
Duration of T.4 timer (per T.30)
Delay
Retransmission from Originating FTE “collides”
with reply from Destination FTE
Timeout occurs without receiving a reply and FTE starts retransmission of original message.
Fax calls are more sensitive to latency than voice calls. Fax protocols in use were established with low latency PSTN connections in mind. The calling fax machine expects a response from the receiving fax machine and if does not receive that response in a set time (usually 3 seconds in automatic mode), retransmits the original message. This constant re-transmission could render a fax relay solution over packet networks inoperable without proper compensation techniques built into the fax over packet solution.
Animations:
8 clicks to bring up groupings.
9th click - next slide
by Naveed Akhtar Bokhari

24. Technique To Keep Call Alive
Originating
FTE
FIU
Destination
Network
FTE ends transmission and starts T4 timer
Delay
Duration of T.4 timer (per T.30)
Delay
Message arrives over
network. FIU remodulates message as it is received.
Before timeout at Originating FTE, FIU starts sending “preamble” fill signal in anticipation of receiving message over network.
Telogy’s Golden Gateway solution provides a robust, patented solution to this latency issue via spoofing techniques. The transmitting fax interface unit “fools” the transmitting fax machine by providing the initial call response it is expecting, and then completes the response as it is received from the “receiving” fax machine.
Animations:
6 clicks to bring up groupings.
7th click - next slide ECO symbol back to main QOS slide
by Naveed Akhtar Bokhari

25. Difference Between a Good Modem and a Great 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
by Naveed Akhtar Bokhari

26. Network Management Challenges Telogy Software Provides
Quality Measurement
Packet Loss
Latency
Jitter
Supervisory Measurement
Call Accounting
Call Type
Configuration
Address Translation
Signaling Mode
Network Environment Parameters
Telogy Software Provides
Quality statistics
Supervisory statistics
Online configuration
Complete SNMP MIB for VOP
Network Management systems are important to equipment manufactures deploying voice over packet solutions. Performance statistics are important in determining proper configuration of such equipment as well as network attributes. Golden Gateway provides information to equipment network management solutions that assists in this process.
Animations:
5 clicks to bring up groupings.
6th click - next slide
by Naveed Akhtar Bokhari

27. Network Management Diagnostics
VOICE MON - Voice Packet Software Monitor
PCM trace capability
Loop back capability
Signal level measurements
Playout statistics
Memory dump facility
SIG MON - Micro Signaling Trace Monitor
Real-time trace capability
Controllable levels of tracing
All significant events including state changes, etc.
Customer can route output to Monitoring System
V. MON - Modem Monitor
Real-time trace capability
Configuration options
Statistics
Status
FAX MON - Fax Software Monitor
Real-time fax trace
All significant events
Millisecond accuracy on timestamping
Compress format interpreted by PC software
In addition to product testing before shipment, built in test is important for VoIP solutions in several ways. First, it can be used by the equipment vendor for testing while integrating the VoIP software into the target equipment during product development. Second, it is important for incorporation as part of the target equipment BIT and network management features.
HIDDEN SLIDE
Animations:
1st click - voice mon box
2nd click - sig mon box
3rd click - fax mon box
4th click - next slide
ECO symbol back to main interoperability slide
by Naveed Akhtar Bokhari

28. Infrastructure Products Broad range of capabilities
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 Products
Telogy Software
Client Suite
Low Density
Multi-Function
Access Products
Telogy Software
Access Suite
Multi-Channel
Multi-Function
Infrastructure Products
Telogy Software
Infrastructure Suite
High Density
Broad range of capabilities
While initial voice and fax over packet solutions were deployed in primarily access and gateway markets, such solutions are needed at low density client applications as well as high density carrier and infrastructure products. It is important to select a vendor that has the focus and resources committed to supporting the full spectrum of the voice and fax over packet market. Use of a single solution in a family of product improves time to market, interoperability and implementation time. The Golden Gateway family of products is segmented by feature requirements and respective pricing to competitively support each of the market segments.
Animations:
4 clicks to bring up groupings.
5th click - next slide
by Naveed Akhtar Bokhari

29. Intellectual 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
by Naveed Akhtar Bokhari

30. Traditional Telephony
Telephones and Fax Machines connect directly with each other over time division multiplexed circuits
Lahore
Karachi
Let’s start from the beginning and explain how telephony is handled today. Voice and fax calls can be viewed as a virtual connection between both endpoints. This is achieved throughout the telephony network via TDM circuits.
by Naveed Akhtar Bokhari

31. Central 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.)
These TDM circuits are connected via central office switches. In addition to routing the calls over these TDM slots, CO equipment performs important billing tasks so that services can be accounted for properly as well as key management operations to assure 24x7 operation.
Analog
Local
Loop
Analog
Local
Loop
Circuit
Switched
Digital
Trunks
by Naveed Akhtar Bokhari

32. Modems
Analog Modem calls are made in the same way as PSTN voice and fax calls
In addition to voice and fax calls over telephony networks, we can perform analog modem connections as well. Have a PC and modem connecting our PC to thenetwork - done through a central office -
Circuit
Switched
Digital
Trunks
Analog
Local
Loop
Analog
Local
Loop
by Naveed Akhtar Bokhari

33. 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
NOW, modem connections over the Internet are performed differently than voice and fax calls over the Internet. As opposed to peer to peer connections that phone calls would normally undergo, modem connections are typically client to server. For example, a PC communicating to a website somewhere on the Internet. The PC modem data is connected to the conetral office as in all analog telephony calls and is routed to a RAS accordingly. THE RAS performs 2 key functions: it acts as a central site for modem calls and performs routing of these calls to the Internet accordingly.
Digital access trunks next to doted line
POP
Packet
Network
WEB
Server
Remote
Access Server
by Naveed Akhtar Bokhari

34. Basics-Analog Voice to PCM
An analog voice signal is received
The Signal is converted to a Pulse Code Modulation (PCM) digital stream

35. Basics-PCM to Frames
The PCM stream is fed into the CODEC
And Voice frames are created
Each Frame is 10 ms long (G.729a) and contains 10 bytes of “speech”

36. Summary
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
by Naveed Akhtar Bokhari