the next killer application? Panel Session Internet Telephony the next killer application? Eugenio Guarene CSELT e-mail: eugenio.guarene@cselt.it

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

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

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

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)

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

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

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

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

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

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

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

PABX-less company R R R R R R X X X VGW LAN Headquarter ATM/FR WAN 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 VGW WS PC PSTN ISDN Dial-up User PC

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