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Tutorial on Technical Challenges Associated
with the Evolution to VoIP

• Presented by
• Susan Spradley President, Wireline Networks
• Alan Stoddard General Manager, Carrier Next
  Generation Networks
• FCC Office of Engineering and Technology
• September 22, 2003

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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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What is Voice over Internet Protocol (VoIP)?
Voice over the Internet (VOI or VON)

Public Internet
QoS Best Effort
Data
Cable
Voice over IP
Managed IP Network
QoS Controlled Load or Guaranteed
Wireline
Wireless
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Telecommunication Network Transitions

• Digital to Packet
• Multimedia, Personalization
• Network Consolidation
• Evolving Regulations
• Multiple Forums Driving Standards

• Analog to Digital
• SS7, CLASS features
• Office Consolidation
• Clear Regulation/Standards

• Analog
• POTS
• Large Offices
• One Chief

Service Drivers
Operation Drivers
Regulation Standards
Packet conversion, like Digital conversion,
driven by Business Case
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VisionConverged Packet Network

• Eliminating Boundaries
• Geographic independence
• Service flexibility
• Service provider reach
• Data-voice network consolidation
• Central office consolidation
• New service opportunities
• Desktop Video
• Application sharing

IP Network
Revenue generating and Cost Saving Opportunities
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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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Digital Switching
VoIP begins with Digital Voice
A D
A/D Converter
In Digital Switching Voice is Data.
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Digital Circuit Switching
LDSwiches
Time Division Multiplexing
SingleByte
TandemOffice
CH0
CH1
CH2

Channels
Channels are ReservedNo Voice and Data
IntegrationHierarchical Design
EndOffice
EndOffice
EngineeredBandwidth
Remote
Remote
WastedBandwidth
Capacity
Maintenance
Engineering
Used Bandwidth
Time
High Network Value but High Network Cost
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Packet Switching
No Tandem LayerNo Remote Layer

• Costs
• Maintenance

Less Equipment
Dynamic Bandwidth Allocation

• Engineering
• Utilization

Flat Network
MaximumBandwidth
Unified Data and Voice

• Value
• Utilization

Unused
DataBandwidth
Capacity
Voice Bandwidth
Time
Voice and Data Coexist
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Dynamic Bandwidth Allocation
Value
TDM
Packet Link
Unused
Trunk Group 1
Data
Trunk Group 2
Voice
Trunk Group 3

• Paths Channelized and Grouped
• Routes Require pre-Engineered
• Unused Channels are Wasted
• No prioritization

• All Bandwidth is available
• Routes Dynamically Switched
• Voice is prioritized
• Data fills unused space

Voice alone gains over 30 higher
utilization Data and Voice Coexist Efficiently
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ATM Cell Switching vs. IP Routing
Synchronous Stream
Asynchronous Stream
Payload
Header
Payload
Header
Cell 0
Cell 1
Cell 2

Variable Length Multi-Byte Packet
Fixed Size Multi-Byte Cells
ATM Core
IP Core
Multi-Byte CellsDynamically Allocated Bandwidth
Reserved Switched per Session Advanced QOS
Variable-Byte Packets No Native Allocation
SchemeNo Native Reservation Scheme Packets are
Routed Independently Limited QOS Routers are
Unaware of Session
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Smart IP Routers and Switches
QoS management at different layers Layer 3 -
DiffServ Prioritizes Packet Routing Layer 2 -
802.1 Q/p Prioritizes Ports and Ethernet Frame-
Fragment large packets on Low Speed Links Layer
1 - Overprovision Bandwidth
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Speech Codecs

• G.711 uncompressed TDM coding PSTN standard
• Compression (reduction in required bit-rate,
  e.g., G.729)
• Accommodate access link speed (e.g., wireless)
• Reduce bandwidth needed in core
• trade off compression against cost
• Concerns
• Baseline voice quality will be lower for lower
  bit-rates
• Increased end-to-end delay
• Reduced performance with expected packet loss
  rates
• Transcoding
• are there other compression codecs in the
  network?
• how often will multiple transcodings occur in a
  complicated path?
• frequency of use for features requiring
  transcoding conferencing, voice mail

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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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The Voice Quality ProblemHow can you know the
voice quality is what you want?
Application layer
Network operator wants A voice quality indicator
Network Engineering Planning Process
Network layer
Manufacturers specify Delay, link utilization,
buffer size codecs available packet loss rate
Need to establish correspondence between the
packet level behavior and the quality perceived
at the application level.
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Engineering VoIP
Network Topology Creator (access type,
equipment, core)
Traffic Profile (loading, voice/ data)
Controllable parameters (voice codec, packet
size, packet loss)
Transport handoff (IP,ATM, TDM, packet
islands, TDM handoff)
Adjustments to Network Design
Analysis of Packet Network Impairments
Predicted Network Performance
Implementation
Operational Measurements(Delay, Packet Loss,
Jitter)
Results Analysis Processing
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ReliabilityMaintaining service during network
failure events

• Design Testing Reliability Before Deployment
• Reliability Analysis H/WS/W Failure rate
  prediction
• System and network failure mode analysis
• Zero Downtime Upgrade and Maintenance by Design
• People Processes Responsiveness Global
  Support
• Traffic assurance verification in Large Office
  test labs
• Large System Integration Centers in all market
  environments Asia, NA, SA, Europe, Asia
• Architecture Engineered for Redundancy
  Survivability
• Self-Healing, Recovers in a Crisis
• Overload Controls incl. Priority Service to
  Essential Services
• Lawful Intercept (CALEA)

"I find that the harder I work, the more luck I
seem to have." - Thomas Jefferson
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Maintaining Security with VoIP
Voice Network Traffic
VoIP Shared Channels
TDM Dedicated Channels
Control (OAMP)
Signaling
Bearer/Data
Public Network
Public Network

• Network Security Hurdles
• Theft of Service
• Service Disruption
• Privacy
• Bearer - eavesdropping
• Signaling collect caller ID / information
• Control - theft of subscriber info

• Remove Security Hurdles
• Strong device authentication
• Secure OAM / Encryption
• Strong operator authentication
• Network partitioning access control
• Voice and signaling accessibility

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Packet Interconnect Between Carriers
Network 2
Network 1
ISUP
Call Server
Call Server
(1) Tandem
(2) Local or Tandem
Packet Network
Offnet Traffic Between Networks - Significant
Growing Percent of Total Minutes
B
C
A
D
GW
GW
GW
GW

• Remove Barriers to Cost Reduction with
  Standardization of
• Signaling Protocols
• Media Protocols
• Services Delivery
• Packet Interconnect Rules Billing Agreements
• Allow Carriers to Maximize Voice over Packet
  Architecture Advantages

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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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Technical Transition Models

• Transition Models
• Enterprise Networks
• IP PBX
• Hosted Services
• VoIP VPNs
• LD Networks
• Local Networks
• Beyond Voice -- Multimedia Networks

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Transition Models

• Overlay - Grow all new line and trunks on VoIP,
  Cap TDM

Evolve - Add IP interfaces to existing TDM
infrastructure, new growth on VoIP

• Rip Replace - Replace existing TDM
  infrastructure with VoIP

Total Cost -
Total Cost -
Total Cost -
Softswitch
Hybrid Softswitch
Softswitch
TDM
Carrier

Carrier Hosted VoIP
Carrier Hosted VoIP
Enterprise
Hybrid IP PBX
PBX or Key System
or

IP PBX
IP PBX
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Enterprise Transition IP PBX

• Evolve - Hybrid IP PBX
• Churn users as needed growth or service
  mobility
• Leverage existing CPE

• Ovrelay (New) / Replace - IP PBX
• New offices or branch sites
• Minimize in-building wiring by using data only
  connection

• Remove Barriers to Profitability
• Retail IP Phones provide cost and feature
  flexibility
• Reduced cost IP connectivity to PSTN
• Enhanced end user mobility (campus-wide)
  increased productivity

Over 25 of the US PBX base expected to be
IP-enabled by year end 2005
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Enterprise Transition Separate Interconnect to
VoIP VPN
VoIP VPN Provider
HQ Site 1
HQ Site 2
PBX Sites

• Converged links local, LD, data
• Simple mgmt, efficient b/w use
• Improved access for remote users

• Separate voice data links
• Separate local PSTN LD connectivity
• Complex mgmt, inefficient b/w use

Remove Barriers to Outsourced Private Networking
Drive New Carrier Revenue / Customer Retention
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Enterprise Transition Hosted VoIP (IP Centrex)

• Evolve Hybrid IP Centrex
• Churn users as needed growth or service
  mobility
• Leverage existing CPE

• Overlay (New) / Replace - IP Centrex
• New offices or branch sites
• Minimize in-building wiring by using data only
  connection

• Remove Barriers to Outsourced Voice Save up to
  35 over IP PBX
• Retail IP Phones provide cost and feature
  flexibility
• Outsource but retain control with improved end
  user management tools and simplified moves, add,
  changes
• Avoid Long Distance charges
• Enhanced user mobility and feature transparency
  campus-wide, at home, remote offices, on the road
  for improved productivity
• Drive High Margin Carrier Revenue Stream -
  Differentiated Service Bundle

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Long Distance Transition
VoIP
VoIP

• Overlay
• Add additional switching nodes
• Groom trunks to new VoIP nodes
• Interconnect inefficiencies between TDM and VoIP

• Evolve / Replace
• Convert or replace existing nodes
• Delay additional switching nodes for later growth
  
• Limit operational expense

• Remove Barriers to Carrier Expansion Service
  Introduction
• Improved Capacity - Relieves CPU Exhaust
• Fewer Trunk Groups, Muxes, X-Connects
  Simplified Trunk Rearrangement
• 15-25 Reduction of Interconnect Ports between
  Switches
• Ability to Address New Markets at Low Cost
• Provide up to 20 Carrier Cash Flow Improvement
  and Packet Infrastructure to Speed IP Services
  Delivery

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Local Network Transition
VoIP

• Overlay
• Add additional switching nodes
• Groom trunks to new VoIP nodes
• Interconnect inefficiencies between TDM and VoIP

• Evolve / Replace
• Convert or replace existing nodes
• Delay additional switching nodes for later growth
  
• Limit operational expense

• Remove Barriers to Carrier Expansion Service
  Introduction
• Eliminate Tandems, X-Connects, Trunking between
  Switch Nodes
• Reduce Switch Nodes by 50-85, Equipment by
  60-80, B/W use up to 30
• Expand Out of Territory at Low Cost
• Retain / Grow Centrex - National Centrex, Centrex
  IP, Churn PBX to Hosted IP
• Provide 10-20 Carrier Cash Flow Improvement and
  Packet Infrastructure to Speed IP Services
  Delivery

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Beyond Voice Multimedia Transition
Multimedia
Existing Phone

• Evolve - Converged Desktop
• Traditional voice services maintained with new
  multimedia add-ons
• Existing desktop retained - new phone upgrades at
  end user driven pace
• Utilizes existing TDM SIMRING or IN
• Enables ubiquitous service delivery

• Overlay (New) / Replace
• IP phone required
• Softclient flexibility PDAs and PCs become
  phones
• Voice becomes a subset of data services bundle
  delivered over DSL or data connection

• Remove Barriers to New Service Introduction
• Simplify communications Personal Communications
  Mgr, Unified Messaging
• Enhance productivity Video Calling
  Conferencing, Web-Push / Co-Browsing
• Provide New Carrier Revenue Stream
  Differentiate Service Set

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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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Business TransitionNetwork separate from Service

• Network Transition
• Competitive Local Cable, W-, CLEC
• Cities/Municipalities?
• More Competitive LD IXC vs LEC
• Data Access
• Res DSL vs Cable
• Biz LEC vs IXC
• Emerging Acccess Implications?
• Wireless LANs
• Fiber to the Home (FTTH)

• Services Transition
• Voice LECs ? to Cable, W-, CLEC
• Video Cable ? Broadband
• IM Yahoo, AOL ? to ASP
• Client Based Services
• SIP Clients
• Peer to Peer
• Napster Model
• Service Provider Based Service
• Yahoo, AOL, Microsoft, Apple
• Business specific Companies
• Bring your own broadband

Separating Service Network permits Service
ubiquity independent of access
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Business TransitionTransition Squabble,
Struggle, Brouhaha
Cable Cos
Yahoo/AOL/MSN
LECs

• Network/Access
• Competitive Carriers Cable, ISPs
• International Carriers ATT
• Data Carriers UUNET
• Res DSL vs Cable
• Biz LEC vs IXC
• Implication of Wireless LANs, Hot spots

• Services
• IM Yahoo, AOL ? to ASP
• Voice LECs ? to Cable, W-, CLEC
• Video Cable ? Broadband
• Next Gen Yahoo, AOL, Microsoft, LECs, IXCs,
  etc.

Apple/Microsoft
Wireless Carriers
Industry Specific (e.g. Banks, Gaming,
Brokerage..)
Cities/ Municipalities
CLECs
IXCs
Market will determine Niche vs End-to-End
providers
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Business TransitionNew Models
Providers move with customer to new Business
Models

• Network Based Services
• Network operators provide Service based on Access
  (Network Services)
• Partnerships Yahoo/SBC - MSN/Verizon
• Mergers?
• Can drive Uniformity/Ubiquity

• Service Provider Based Services
• ISPs offer ad hoc, interpersonal communications
  brokerage
• Bring your own broadband
• Fwd.pulver.com, IM, Email
• Reliability required? Wiretap required?

• Client Based Services
• Peer-to-Peer
• Web/Napster
• Pre-arranged Address exchange
• SIP based clients

Regulation will impact viability of new Business
Models
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Agenda

• Introduction
• IP Telephony Overview
• Technical Considerations
• Technical Transition Models
• Business Transition Models
• Conclusions

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Conclusions

• Technology is decoupling Service from Access
• Users desire ubiquitous service access,
  personalization and the freedom of mobility
• There are technology challenges that need to be
  considered in developing and deploying IP
  Telephony
• There are both technical transition and business
  transition models to consider