Politecnico
di Milano
Internet Telephony:
Technology Standards & Business
Maurizio Dècina
Politecnico di Milano
Convegno CNIPA
Tecnologie Voice over IP come opportunità per la PA
Roma, March 17, 2005
Slide 1
Open Networking Architecture
Networked Applications
Email, Fax, Telephony,, Videoconferencing, Television,…
E-games, Web Browsing, Videostreaming,…
Interactive Education, Interactive Television, Financial Services,…
Interoperability (Middleware)
Name Servers, Security, Privacy, Directories, Electronic Money,...
Distributed Computing, Transportable Programs & Intelligent Agents
Internetworking
TCP/UDP end-to-end transport
IP DiffServ & IntServ Flows
Interconnection
Telecom Services: POTS, ISDN, ATM, Wireless,…
Television Services: CATV, Digital Video Broadcasting, DTT, …
Data Pipes: Modem: POTS, ISDN, DSL, Cable,…
Data: LAN, X.25, Frame Relay,…
Leased Line: T1/E1, T3/E3, SONET/SDH,…
M. DECINA: "Internet e l’infrastruttura globale dell’informazione" (Internet and the Global Information
Infrastructure), Notiziario Tecnico Telecom Italia, vol. 6, n. 2, Ottobre 1997.
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Voice over IP Packets
VoIP Capacity Issues
20ms @ 8kbit/s yields 20 byte payload
of compressed voice and 40 byte header
IP Header (20)
UDP (8)
RTP (12)
Header is 40 bytes
Politecnico di Milano
©2005 Maurizio Dècina
Maurizio Dècina - Convegno Teach - Milano, May 11, 1999
-3-
PAYLOAD : 20
31
CNIPA VoIP, Rome, March 17, 2005
3 Faces of Convergence
Communications
Fixed to Mobile
Convergence
Convergence
Convergence
Broadcast to Unicast
Convergence
Source: M. Dècina, 2004
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Full IP Network
Network Environment
Wired
Access
Mobility, Location,
Connection & Control
Servers
FTTx RSU
RSU
xDSL+
Internet
Application
Platforms
Broadband
Gateway
Internet
Application Servers
Service Environment
LRE
Wireless
Access BTS
Internet
2G/3G+
AP
Mobility
Gateway
IP Backbone
Intelligent Edge
Wi-Fi/WiMAX+
Media
Gateway
PSTN/ISDN
Source: M.Dècina, 1999, updated 2003
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Broadband Access: the Bandwidth Gap
Bandwidth
10G/40G
10/100/1000
E1 Lines
LAN
Metro
Edge
ADSL
ADSL2
ADSL2+
FTTx
WiEth
©2005 Maurizio Dècina
Metro
Core
2-4 Mb/s
4-8 Mb/s
25 Mb/s
x000 Mb/s
X00 Mb/s
-6-
WAN
Existing
Copper
Fiber
Wireless
CNIPA VoIP, Rome, March 17, 2005
Residential Broadband Access
Incumbent
ULL site
DSLAM
Wi-Fi
Access
Point
•Telephony Services
•Internet Access (up to 20 Mbit/s)
•Live TV, VoD, and Video Streaming
•Videocommunication
IAD
IAD
STB
©2005 Maurizio Dècina
TRIPLE PLAY SERVICES over DSL
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CNIPA VoIP, Rome, March 17, 2005
Windows Media Center
One device for home personal management of multimedia entertainment and
information appliances
User – friendly interface for the entire family
Remote Control
Input:
DVB-T
Cable – SAT
Analog TV
Internet (VoD – Napster, ESPN, Sonic, etc.)
Feature
Video: MPEG-2, dvr-ms, XVID & DIVX v3/v5
http://www.microsoft.com/windowsxp/mediacenter
Audio Format: Wav, MP3, WMA
Web browsing: Internet Explorer 6
Shared Internet Access
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Evolving Wireless Communications
CABLE
PAN
REPLACEMENT
ZigBee
802.15.4
Range
CITY,
WMAN
SUBURBS
1 kbit/s
MobileFi
802.20
GSM
ED
GPRS EDGE
10 kbit/s
100 kbit/s
UMTS
1 Mbit/s
WiMAX
802.16a/e
FULL
COUNTRY,
REGION
WAN
WIDE
802.11a/g/n
HSDPA
10 Mbit/s
100 Mbit/s
1 Gbit/s
Bit Rate
Source: M. Dècina, 2004
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Mobility
Wi-Fi
802.11b
PUBLIC ACCESS WLAN
LIMITED
HOME, OFFICE
UltraWideBand
802.15.3
Bluetooth
802.15.1
MobileFi, aka 802.20, vs. 3G
Source: Guy Pujolle, 2003
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
3 Faces of Internet Telephony
Internet Phones
Carrier Phones
ASP VoIP
NGN VoIP
Internet
Telephony
Wireless Phones
Wi-Fi VoIP
Source: M. Dècina, 2004
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Telephony/Internet Transition
2002-2012
SIGNALLING
SS-7
2 Billion+
Wired & Wireless
Telephone Users
POTS, ISDN,
GSM, UMTS,..
SIP
2 Billion+
Wired & Wireless
Internet Users
SOFT
SWITCH
MEDIA
GATEWAYS
circuits
packets
@ Mid Transition
2007
Next Generation
Internet
IP v6
POTS, ISDN, DSL, FFTx,…
UMTS,.WiFi,.WiMAX..
Source: M. Dècina, 2002
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
NGN Voice - Architectural Transition
Border Zone
Core Zone
TDM
switch
TDM
switch
OLO
PSTN
Access Zone
Residential Zone
POTS
phone
Operator’s PSTN Network
CL5 TDM switch
CL4 TDM
switch
PABX
TGW
SGW
Directories
TGW
SGW
AGW
OLO IP
Operator’s IP Network
SBC
Softswitch
Interworking functions
 SGW: converts IP signalling
to PSTN/ISDN signalling
 TGW: converts IP data flow
to PCM
 SBC: interconnects two VoIP
network via IP
 TDM switch: Call controll &
Call routing towards the
PSTN/PLMN network
©2005 Maurizio Dècina
Class 4 Replacement
functions
 SOFTSWITCH: controls call
routing & call set-up for CL 4/5
replacement
 DIRECTORIES: advanced routing
information
IN & Multimedia
service platform
functions
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Class 5 Replacement,
offloading functions
User equipment
 AGW: encapsulates user’s
signalling on IP and converts
PCM to IP data flow
 SGW: converts IP signalling to
PSTN/ISDN signalling
 TGW: converts IP data flow to
PCM
 POTS, PABX:
generates user
signalling, tx and rx
user voice data
CNIPA VoIP, Rome, March 17, 2005
Skype p2p Internet Telephony
•
•
•
•
29 m users, 85 m dowloads
Proprietary SW, POTS quality, strong privacy
Free PC-to-PC calls
1 m users of “SkypeOut”: PC-to-Phone
170 Countries
March 2005
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Web Telephony Features
PC Telephony
Public PC Telephony
Multiparty conference
Address book, Finder
Centralized Directory
Click2Dial
Mail-to-Speak
Integration with Microsoft Outlook
Presence
Instant Messaging
Chatting, SMS, MMS and EMS
Videomessaging
Videocommunication
Nomadic access (safe individual connection from Everywhere)
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Microsoft Live Communications Server
Microsoft Passport Digital Identity, Microsoft Active Directory, Microsoft
Windows Media Center, …
Microsoft Live Communications Server
Uses SIP based Telephony, as part of the Instant Messaging Service, and
includes
telephony capabilities, IM, notification, conferencing, messaging and
presence functionality
a desktop “dashboard” to provides access to functions and administration
methods of integrating directly with business applications, and a range of
mobility capabilities
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
SIP Entities – Multimedia over the Internet
User Agent Client (UAC)
Redirect Server
End systems
Send SIP requests
“Network” server; redirects users to try
other server
Proxy Server
User Agent Server (UAS)
Listens for call requests
Prompts user or executes program to
determine response
User Agent
“Network Server” Proxies request to
another server Can “fork” request to
multiple servers, creating a search tree
Registrar
receives registrations regarding current
user locations
UAC + UAS
Request
Response
Media
SIP Proxy
2
SIP Redirect
Server
3
5
4
1
11
12
SIP Client
13
14
6
SIP Proxy
10
7
SIP Proxy
8
9
SIP Client
(User Agent Server)
Source: H.Schulzrinne, 1999
©2005 Maurizio Dècina
Location Service
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CNIPA VoIP, Rome, March 17, 2005
SIP - Beyond Voice
Internet
DNS
Phone number to reach any
device on IP or PSTN
ENUM
query
AOR to
Contact
Address
SIP-1
SIP-2
Gateway
Internet
TDM
PSTN
Switch
PSTN
Presence, phone number or URL to reach
any device on IP or PSTN
IP communications are integrated
with applications
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Converged Network Solutions
Main site
Remote site 1
Survivable
Remote
Gateway
Multi-Media
Mobile
Working
SIP SERVER
WAN
Remote site 2
Survivable
Remote
Gateway
©2005 Maurizio Dècina
PSTN
- 19 -
Voice Specialty
Converged
WiFiIP, TDM, analog
CNIPA VoIP, Rome, March 17, 2005
Converged Services & Devices
Service Content
Broadcast
Mobile
Fixed
IP
Network
Personal
Digital
Environment
User
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005
Sistema Pubblico di Connettività - SPC
PROVIDER
QUALIFICATI
Provider 1
Asp 2
Asp 1
Provider 2
Internet
RUPAR
Provider 3
Internet qualificata
…
PAC
PAL
PAC
ISP Locale
PAL
RUPAR
LISTINO
SERVIZI
Provider 1
IP BE 2Mbps x€
IP BE 100 Mbps
y€
….
Provider 2
IP HQ 2Mbps k€
IP HQ 100 Mbps
z€
PAC
ISP Regionale
RUPAR
ISP Nazionale
PAL
Asp
3
T
T
O
RI
N
O
MILANO
GENOVA
Struttura di gestione
della sicurezza
VENEZIA
BOLOGNA
FIRENZE 3
PERUGIA
ROMA
TRIESTE
ANCONA
L’AQUILA
CAMPOBASSO
NAPOLI
CAGLIARI
CATANZARO
PALERMO
Struttura di gestione
della qualità
©2005 Maurizio Dècina
BARI
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Cittadini e imprese
Fonte: CNIPA, 2003
CNIPA VoIP, Rome, March 17, 2005
Rete Internazionale delle PA - RIPA
Fonte: CNIPA, 2004
©2005 Maurizio Dècina
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CNIPA VoIP, Rome, March 17, 2005