1. the next killer application?
Panel Session
Internet Telephony
the next killer application?
Eugenio Guarene
CSELT

2. Voice over IP services Internet Telephony Voice/data integration
PC-to-PC
PC-to-Phone
Phone-to-Phone
IP-Fax
Voice/data integration
Corporate
Value added services
Call centres
CSCW
Web help desk

3. Basic elements for a service architecture
Directory Server
Messaging
Server, VAS
Network
Mgmt
Billing
Server
Client PC
Gatekeeper
Client PC
IP network
PSTN
Vocal
Gateway
Vocal
Gateway

4. Protocol efficiency: RTP/UDP/IP
Version
HLen
TOS
Total Length
Identification F
Fragment Offset
IP header
5 words 20 bytes
TTL
Protocol
Header Checksum
Source Address
Destination Address
2 words 8 bytes
UDP header
Source Port
Destination Port
Message Length
Checksum (optional)
V=2 P X CC M PT
Sequence Number
3 words 12 bytes
RTP header
Time Stamp
Synchronization SouRCe (SSRC) identifier
Payload

5. Bandwidth and statistical multiplexing
Measured in a window of 250ms 32 28 24 20
Bandwidth (kbit/s) 16 12 8 4 50
100
150
200
250
300
350
400
Time (sec)

6. Dalay budget total delay Look Ahead Frame Coder TX Look Ahead Frame
Contribution
Frame
Look Ahead
TX processing
Network
Originated by
the network
RX buffering RX
contribution
RX processing
total delay

7. Network delay and jitter control
Data Pkt
Voice Pkt
PBX
PBX GW GW
IP WAN R R

8. multiservice carriers
Sea Bulk Phone
Access of
multiservice carriers
to SEA-BONE
SEA-BONE
Internet trunks
R u s s i a
Internet
Local and regional
Service Providers R
IWF
I n d i a
INTL
EXCH
I s r a e l
International PSTN
PSTN
trunks

9. Sea Bulk Phone “Toll Quality” “Toll Quality” Internet
ITSP GK
Local
PSTN
SEA BONE
SBP
Server GW B
Billing
International
PSTN
“Toll Quality” GW
ITSP GK GW
Local
PSTN GK
Internet A
“Internet Quality”
ITSP

10. Product evaluation A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M A B C D E F G H I J K L M
A: Core End side PSTN interface B: Core End side implementation C: Edge End side - PSTN Interface
D: Edge End side Implementation E: Voice Transport Techniques F: Routing of Calls
G: Networking Security Issues H: Voice coding & QoS performance I: Network management
J: Service management K: Equipment requirements L: End-user service feature
M: Organizational & technical assistance

11. Corporate Communications
LAN PC R
Headquarter
ATM/FR WAN WS PC
SOHO
LAN R PC
Corporate
Backbone
IP WAN
--> Internet R
Remote Site X R WS
LAN R
NAS PC
LAN X R X
LAN PC WS WS PC
PABX
PABX
PSTN
ISDN
Dial-up User PC

12. Voice-data integration
LAN PC R
Headquarter
ATM/FR WAN WS PC
SOHO
LAN R PC
Corporate
Backbone
IP WAN
--> Internet R
Remote Site X R WS
LAN R
NAS PC
LAN X R X
LAN PC WS WS PC
PABX
VGW
VGW
PABX
PSTN
ISDN
Dial-up User PC

13. PABX-less company R R R R R R X X X VGW LAN Headquarter ATM/FR WANPC R
Headquarter
ATM/FR WAN WS PC
SOHO
LAN R PC
Corporate
Backbone
IP WAN
--> Internet R
Remote Site X R WS
LAN R
NAS PC
LAN X R X
LAN PC WS
VGW WS PC
PSTN
ISDN
Dial-up User PC

14. Voice-data application: an example
Local PoP
PPP to IP gateway
Server
Merchant central site
LAN CO
Internet
Router
Web server GW
Local stores