IPTalk: Bringing DSS1-like Services to IP Telephony

1. IPTalk: Bringing DSS1-like Services to IP Telephony

2. VoIP - Definition Phone traffic (Voice) over Internet Regular terminals (TEs) & access networks IP in the backbone Motivation: cheap IP bandwidth Voice over IP-networks IP TEs & access-network typically Ethernet Motivation: IP traffic growth (10 times faster than voice) New access networks Integration of telephony and data services (CTI) One single network for data / voice

3. IPTalk: A VoIP Demonstration and Experimentation Platform Low cost terminal (TE) High voice quality Plug & Play ISDN type of Services Integration with (Data-) Applications

4. IPTalk: Addressed Problems Delay Network delay jitter (QoS) End system delay (PC type terminals) Signaling Services Charging (,Accounting, Billing) Network QoS End system cost Intelligence at the edge requires �complex� signaling SW in the TE

5. Users & Markets LAN Telephony Low latency, high capacity, low cost, low utilization (Virtual) private networks Intra-company telephony Building wiring Single network infrastructure Access networks Cable modems, xDSL

6. Delay

7. Reducing Delay (< 100ms) Simpler (synchronous) TE design Smaller packets Smaller headers (header compression) Reduces delay on slow links Improves efficiency Faster access networks (Ethernet) Diffserv (lower jitter) => less buffering

8. Terminal Architecture

9. HW Picture

10. TE Components & Cost IP ISDN MCU $15 $10 Phy + Net. Interface $12 $10 CODEC (voice grade) $5 $5 RAM, ROM (flash) $20 -1 Housing $5 $5 Headset $5 $5 Board, resistors, caps., oszil., $20 $15 Total $82 $50 1 RAM, ROM integrated in MCU

11. System Cost TE more expensive than ISDN (&POTS) �Faster� CPUs complex access protocol CSMA/CD complex signaling SW (larger storage) Network less expensive and easier to manage

12. Network Architecture QoS Network (Diffserv) E.164 type numbering (simpler client) Multicast & Server-based Address Resolution (scalability) Gateway to PSTN with least cost routing Integrated admission control and charging

13. Network Architecture

14. Call Signaling No established standard in the IP world H.323 (most established, complex, inflexible) SIP/SDP (simple, unfinished e.g. missing service definitions) MGCP (centralized approach, good for convergence)

15. Signaling DSS1 Services in SIP 27 services in DSS1 SIP TE-to-TE Vs. DSS1 TE-to-network Compatibility with NAT & firewalls Plug & Play (standalone, self configuration, server free clients) Scalability Use E.164 type numbering plan

16. Call Setup with Reservation Basic call setup (TE-to-TE) QoS signaling (TE-to-network) AOC Information (network-TE) Split-charge model (network-TE)

18. DSS1: ITU-T Rec.: Q.931 & Q.95x Number Identification Call Offering Call Completion Multiparty Community of Interest Charging Additional Information Transfer

19. Supplementary Services

20. Calling Line Identification Presentation Connected Line Identification Presentation Calling Line Identification Restriction Connected Line Identification Restriction

21. Call Forwarding Unconditional Call Forwarding Busy Call Forwarding No Reply Explicit Call Transfer

22. Call Hold Call Waiting Three Party Conference

31. Extensions to SIP INFO Method (User-User signaling, AOC) INQUIRE Method (least cost routing) Header-Fields: Also

32. Summary IPTalk: Architecture for end-to-end VoIP Low end-to-end delay Needs Admission control (or over-provisioning) DSS1 Services can be provided in Internet style end-to-end signaling. Hiding of IP addresses (CLIR, CLOR) => NAT Reservation (QoS) and charging centralized approach Low cost terminal architecture

33. Open Issues In field service deployment Multi-provider Diffserv signaling (SLA Trading) Charging models (not only split charges) Accounting, Billing