Tutorial on Technical Challenges Associated with the Evolution to VoIP

1
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

2
Agenda

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

3
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
4
Telecommunication Network Transitions
Digital to Packet Multimedia, Personalization
Network Consolidation Evolving Regu
lations
Multiple Forums Driving Standards
Analog to Digital SS7, CLASS features Offi
ce Consolidation Clear Regulation/Standa
rds

Analog POTS Large Offices One Ch
ief

Service Drivers
Operation Drivers
Regulation Standards
Packet conversion, like Digital conversion,
driven by Business Case
5
VisionConverged Packet Network
Eliminating Boundaries Geographic independence
Service flexibility Service provider reach Data-
voice network consolidation Central office conso
lidation New service opportunities Desktop Video
Application sharing
IP Network
Revenue generating and Cost Saving Opportunities
6
Agenda

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

7
Digital Switching
VoIP begins with Digital Voice
A D
A/D Converter
In Digital Switching Voice is Data.
8
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
9
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
10
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 priorit
ization
All Bandwidth is available Routes Dynamically Swi
tched Voice is prioritized Data fills unused spa
ce
Voice alone gains over 30 higher utilization
Data and Voice Coexist Efficiently
11
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 Scheme
No Native Reservation Scheme Packets are Routed
Independently Limited QOS Routers are Unaware of
Session
12
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
13
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

14
Agenda

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

15
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, b
uffer size
codecs available packet loss rate
Need to establish correspondence between the
packet level behavior and the quality perceived
at the application level.
16
Engineering VoIP
Network Topology Creator (access type, equipme
nt, core)
Traffic Profile (loading, voice/ data)
Controllable parameters (voice codec, packet si
ze,
packet loss)
Transport handoff (IP,ATM, TDM, packet islan
ds,
TDM handoff)
Adjustments to Network Design
Analysis of Packet Network Impairments
Predicted Network Performance
Implementation
Operational Measurements(Delay, Packet Loss,
Jitter)
Results Analysis Processing
17
ReliabilityMaintaining service during network
failure events
Design Testing Reliability Before Deployment
Reliability Analysis H/WS/W Failure rate
prediction System and network failure mode analys
is Zero Downtime Upgrade and Maintenance by Desig
n People Processes Responsiveness Global Su
pport Traffic assurance verification in Large Off
ice test labs Large System Integration Centers in
all market environments Asia, NA, SA, Europe,
Asia Architecture Engineered for Redundancy Su
rvivability Self-Healing, Recovers in a Crisis O
verload 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
18
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 Servi
ce Disruption Privacy Bearer - eavesdropping Si
gnaling 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

19
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

20
Agenda

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

21
Technical Transition Models

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

22
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
23
Enterprise Transition IP PBX
Evolve - Hybrid IP PBX Churn users as needed gr
owth 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
24
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 u
se
Remove Barriers to Outsourced Private Networking
Drive New Carrier Revenue / Customer Retention
25
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

26
Long Distance Transition
VoIP
VoIP
Overlay Add additional switching nodes Groom
trunks to new VoIP nodes Interconnect inefficien
cies between TDM and VoIP
Evolve / Replace Convert or replace existing nod
es Delay additional switching nodes for later g
rowth
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

27
Local Network Transition
VoIP
Overlay Add additional switching nodes Groom
trunks to new VoIP nodes Interconnect inefficien
cies between TDM and VoIP
Evolve / Replace Convert or replace existing nod
es Delay additional switching nodes for later g
rowth
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

28
Beyond Voice Multimedia Transition
Multimedia
Existing Phone
Evolve - Converged Desktop Traditional voice ser
vices maintained with new multimedia add-ons
Existing desktop retained - new phone upgrades at
end user driven pace Utilizes existing TDM SIMRIN
G or IN Enables ubiquitous service delivery
Overlay (New) / Replace IP phone required Soft
client 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 Vi
deo Calling Conferencing, Web-Push /
Co-Browsing Provide New Carrier Revenue Stream
Differentiate Service Set
29
Agenda

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

30
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? Wire
less LANs Fiber to the Home (FTTH)
Services Transition Voice LECs ? to Cable, W-,
CLEC Video Cable ? Broadband IM Yah
oo, AOL ? to ASP Client Based Services SIP Clie
nts Peer to Peer Napster Model Service Provider
Based Service Yahoo, AOL, Microsoft, Apple Busi
ness specific Companies Bring your own broadband

Separating Service Network permits Service
ubiquity independent of access
31
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 Implica
tion of Wireless LANs, Hot spots
Services IM Yahoo, AOL ? to ASP Voice LECs ?
to Cable, W-, CLEC Video Cable ? Broa
dband Next Gen Yahoo, AOL, Microsoft, LECs, IX
Cs, 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
32
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.co
m, IM, Email Reliability required? Wiretap requi
red?
Client Based Services Peer-to-Peer Web/Napster
Pre-arranged Address exchange
SIP based clients
Regulation will impact viability of new Business
Models
33
Agenda

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

34
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