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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. Agenda. Introduction - PowerPoint PPT Presentation
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FCC – Office of Engineering and Technology
“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 TechnologySeptember 22, 2003
FCC-OET 9/22/03 -- 2
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 3
What is Voice over Internet Protocol (VoIP)?
Public
Internet
“Managed”IP Network
QoS = Best Effort
QoS = Controlled Load orGuaranteed
Voice over the Internet (VOI or VON)
Voice over IPCable
MTA
VideoFeed
CMTS
Data
Wireless Wireline
PublicInternet
FCC-OET 9/22/03 -- 4
BETTY JONES 1:05919-992-1295
Service Drivers
OperationDrivers
Regulation&
Standards
VoiceDataVideo
Telecommunication Network Transitions
Analog to DigitalSS7, CLASS features
Office Consolidation
Clear Regulation/Standards
Digital to PacketMultimedia, Personalization
Network Consolidation
Evolving Regulations
Multiple Forums Driving Standards
AnalogPOTS
Large Offices
One Chief
Packet conversion, like Digital conversion, driven by Business CasePacket conversion, like Digital conversion, driven by Business Case
FCC-OET 9/22/03 -- 5
VisionConverged Packet Network
IP Network
VideoDataVoice
• Eliminating Boundaries– Geographic independence
– Service flexibility
– Service provider reach
• Data-voice network consolidation
• Central office consolidation
• New service opportunities– Desktop Video
– Application sharing
Revenue generating and Cost Saving OpportunitiesRevenue generating and Cost Saving Opportunities
FCC-OET 9/22/03 -- 6
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 7
VoIP begins with Digital Voice
Digital Switching
In Digital Switching …
… Voice is Data.
AD
A/D Converter
FCC-OET 9/22/03 -- 8
Digital Circuit Switching
Channels
SingleByte
Time Division Multiplexing
CH0 CH1 CH2 …
EngineeredBandwidth
Time
Cap
acity
WastedBandwidth
Engineering Maintenance
EndOffice
TandemOffice
LDSwiches
Remote Remote
EndOffice
Channels are ReservedNo Voice and Data Integration
Hierarchical Design
High Network Value but … High Network Cost
Used Bandwidth
FCC-OET 9/22/03 -- 9
Packet Switching
Unified Data and
Voice
EndOffice
Flat Network
No Tandem LayerNo Remote Layer
Time
Cap
acity
DataBandwidth
MaximumBandwidth
Voice and Data Coexist
Remote
• Costs• Maintenance
Engineering Maintenance
Less Equipment
Dynamic Bandwidth Allocation
• Engineering• Utilization
• Value• Utilization
Voice Bandwidth
Unused
FCC-OET 9/22/03 -- 10
Dynamic Bandwidth Allocation
• Paths Channelized and Grouped• Routes Require pre-Engineered• Unused Channels are Wasted• No prioritization
Value
Packet Link
Data
Unused
Voice
Trunk Group 1
Trunk Group 2
Trunk Group 3
TDM
• All Bandwidth is available• Routes Dynamically Switched• Voice is prioritized• Data fills unused space
Voice alone gains over 30% higher utilizationData and Voice Coexist Efficiently
FCC-OET 9/22/03 -- 11
ATM Cell Switching vs. IP Routing
Multi-Byte CellsDynamically AllocatedBandwidth ReservedSwitched per Session
Advanced QOS
Synchronous Stream
Cell 0 Cell 1 Cell 2 …
EndOffice
ATM Core
EndOffice
Variable-Byte PacketsNo Native Allocation Scheme
No Native Reservation SchemePackets are Routed Independently
Limited QOSRouters are Unaware of Session
Asynchronous Stream
PayloadHeader
Variable Length Multi-Byte PacketFixed Size Multi-Byte Cells
PayloadHeader
EndOffice
IP Core
EndOffice
FCC-OET 9/22/03 -- 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 LinksLayer 1 - Overprovision Bandwidth
CAT 5, Fiber
ETHERNET
ATM, etc.
Interface
CAT 5, Fiber
ETHERNET
ATM, etc.
InterfaceDiffServ
802.1 Q/p
Layer 1
Physical
Layer 2
Data Link
Layer 3
Network
IP
Bandwidth
DiffServ
802.1 Q/p
Layer 1
Physical
Layer 2
Data Link
Layer 3
Network
IP
Bandwidth
DesMac t
SourceMac
802.1 Q Tag
• Priority Bits
• VLAN ID
Protocol
TypePayload
802.1 Q Tag
•Priority Bits
•VLAN ID
Version Header Length
32 Bits 16 Bits 48 Bits48 Bits
First 16 Bits of IP Data Gram
4 Bits 4 Bits 8 Bits
Ethernet Frame
DSCPField (ToS)
DesMac
SourceMac
802.1 Q Tag
• Priority Bits
• VLAN ID
Protocol
TypePayload
802.1 Q Tag
•Priority Bits
•VLAN ID
Version Header Length
32 Bits 16 Bits 48 Bits48 Bits 512 - 12000Bits
First 16 Bits of IP Data Gram
4 Bits 4 Bits 8 Bits
Ethernet Frame
DSCPField (ToS)
FCC-OET 9/22/03 -- 13
Speech Codecs
G.711: “uncompressed” TDM coding: PSTN standardCompression (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
FCC-OET 9/22/03 -- 14
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 15
Application layerNetwork operator wants:A voice quality indicator
Network layer
Manufacturers specify:Delay, link utilization, buffer sizecodecs available packet loss rate
The Voice Quality Problem:How can you know the voice quality is what you want?
Need to establish correspondence between the packet level behavior and the quality perceived at the application level.
Network Engineering Planning Process
FCC-OET 9/22/03 -- 16
Engineering VoIP
Adjustments to Network
Design
Analysis of Packet Network Impairments Predicted Network Performance
Operational Measurements(Delay, Packet Loss, Jitter)
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)
Results Analysis & Processing
Implementation
FCC-OET 9/22/03 -- 17
ReliabilityMaintaining service during network failure events
• Design & Testing: Reliability Before Deployment
─ Reliability Analysis: H/W+S/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
FCC-OET 9/22/03 -- 18
Control (OAM&P)
Signaling
Bearer/Data Public Network
Voice Network Traffic
Maintaining Security with VoIP
VoIP
Shared Channels
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
TDM
Dedicated Channels
Public Network
FCC-OET 9/22/03 -- 19
Packet Interconnect Between Carriers
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
TDM Office
CallServer
CallServer
PacketNetwork
ISUP
(1) Tandem (2) Local or Tandem
B CA
Packet Bearer Path
Signaling Path
TDM Bearer Path
KeyNetwork 1 Network 2
GW
D
CallServer
CallServer
TDM Office
GWGWGW
Offnet Traffic Between Networks - Significant & Growing Percent of
Total Minutes
FCC-OET 9/22/03 -- 20
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 21
Technical Transition Models
• Transition Models • Enterprise Networks
– IP PBX
– Hosted Services
– VoIP VPNs
• LD Networks• Local Networks • Beyond Voice -- Multimedia Networks
FCC-OET 9/22/03 -- 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
Car
rier
E
nter
pris
e
TDM
PBX or Key System
Softswitch
IP PBX
Carrier Hosted VoIP
Hybrid Softswitch
Hybrid IP PBX
Softswitch
IP PBX
Carrier Hosted VoIP
Total Cost - $$ Total Cost - $ Total Cost - $$$
or
+
+
FCC-OET 9/22/03 -- 23
Enterprise Transition IP PBX
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
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
Over 25% of the US PBX base expected to be IP-enabled by year end 2005
FCC-OET 9/22/03 -- 24
•Converged links – local, LD, data•Simple mgmt, efficient b/w use •Improved access for remote users
Enterprise Transition Separate Interconnect to VoIP VPN
•Separate voice & data links •Separate local PSTN & LD connectivity•Complex mgmt, inefficient b/w use
Key System
Sites
PBXSites Centrex
Sites
HQ Site 1
HQ Site 2
VoIP VPNProvider
IP CentrexSites
IP PBXSites
DataProvider
LDProvider
LocalProvider
IP CentrexSites
Key SystemSites
IP PBXSites
PBXSites Centrex
Sites
HQ Site 1
HQ Site 2
Remove Barriers to Outsourced Private Networking Drive New Carrier Revenue / Customer Retention
FCC-OET 9/22/03 -- 25
Enterprise Transition Hosted VoIP (IP Centrex)
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
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
FCC-OET 9/22/03 -- 26
Long Distance Transition
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
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
VoIP VoIP
FCC-OET 9/22/03 -- 27
Local Network Transition
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
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
VoIP VoIP
FCC-OET 9/22/03 -- 28
Beyond Voice – Multimedia Transition
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
Multimedia Existing Phone
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
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
FCC-OET 9/22/03 -- 29
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 30
Business TransitionNetwork separate from Service
Separating Service & Network permits Service ubiquity independent of accessSeparating Service & Network permits Service ubiquity independent of access
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
FCC-OET 9/22/03 -- 31
Business TransitionTransition Squabble, Struggle, Brouhaha
Market will determine Niche vs End-to-End providersMarket will determine Niche vs End-to-End providers
Cable Co’s
LECs
WirelessCarriers
IXCs CLECs
Yahoo/AOL/MSN
Apple/Microsoft
Industry Specific(e.g. Banks, Gaming,
Brokerage..)Cities/Municipalities
Network/Access• Competitive Carriers: Cable, ISPs
• International Carriers: AT&T
• 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.
FCC-OET 9/22/03 -- 32
Business TransitionNew Models
Regulation will impact viability of new Business ModelsRegulation will impact viability of new Business Models
Client Based Services• Peer-to-Peer• Web/Napster• Pre-arranged Address exchange• SIP based clients
Network Based Services• Network operators provide Service based on
Access (Network + Services)• Partnerships: Yahoo/SBC - MSN/Verizon• Mergers?• Can drive Uniformity/Ubiquity
Providers move with customer to new Business ModelsProviders move with customer to new Business Models
Service Provider Based Services• ISPs offer ad hoc, interpersonal
communications brokerage• Bring your own broadband• Fwd.pulver.com, IM, Email• Reliability required?
Wiretap required?
FCC-OET 9/22/03 -- 33
Agenda
Introduction
IP Telephony Overview
Technical Considerations
Technical Transition Models
Business Transition Models
Conclusions
FCC-OET 9/22/03 -- 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