1. SIP-ENUM-- --- S.,L. Chou 1 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP/ENUM 與 VoIP 產業應用 周勝鄰 博士 工研院電通所 E-mail: slchou@itri.org.tw Tel: 03-5915616 2004. 3. 11slchou@itri.org.tw

2. SIP-ENUM-- --- S.,L. Chou 2 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Contents  Overview of VoIP System  VoIP Technologies --- From H.323 to SIP  SIP-based IP Multimedia Communication System  ENUM for IP-PSTN Convergence  Conclusion

3. SIP-ENUM-- --- S.,L. Chou 3 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP 的過去  Born of VoIP Industry VoIP Phone --- VocalTech 1995  H.323 Standard for VoIP Industry H.323 Proposed by ITU-T for Multimedia Communication over LAN in 1996 Adopted Quickly and Widely by Industries  VoIP Gateway, Gatekeeper, Enterprise GW, IAD Mainly Used in Enterprise, Toll-by-Pass Applications  Market Slow Down Infrastructure Bottleneck --- Limitation of H.323 New Technologies Developed Users Hesitate to Buy H.323 Products Vendors Invest Much in H.323

4. SIP-ENUM-- --- S.,L. Chou 4 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP 的現在  New Technologies Ready MGCP, MEGACO/H.248, SCTP/M3UA, SIP/SDP IETF-like Protocols  New Products Developed Most Upgraded from H.323 Products  Support New Technologies as well as H.323 VoIP Infrastructure  Softswitch, Trunk GW, SS7 Signaling GW (SS7 over IP) Market Re-Booming  IETF Technologies Dominate SIP Telephony Being Widely Accepted ENUM for IP/PSTN Convergence Being Developed  Softswitch vs. SIP Softswitch: Mainly for Class 4/5 Switch Replacement SIP: Provide Telephony from IP’s Point of View

5. SIP-ENUM-- --- S.,L. Chou 5 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP 的未來  VoIP Infrastructure will Get Ready (How Soon ?) ENUM for IP/PSTN Convergence Product and Service Start to Boom  It’s Technologies Trend, Not Just for Cost Saving Driving Force of NGN Mandatory in Future All-IP Network  SIP Technologies Will Dominate SIP Telephony/CO Signaling/Multimedia Service/3G Key Technologies for IP/PSTN Convergence  VoIP in 3G and B3G 3G IMS VoIP over WLAN/Cellular Integration

6. SIP-ENUM-- --- S.,L. Chou 6 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 QoS Issues  Issues Reliability/Throughput/Security Delay/Jitter/Packet Loss/Echo/…  End-to-End Quality Guarantee ?  Internet for VoIP ? Implementation of QoS  RVSP, Diff. Serv, …  Dedicated Managed IP Network !!

7. SIP-ENUM-- --- S.,L. Chou 7 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 QoS Issue TIPHON Network Delay Requirements 150 250 350 450 0 50 100 150 200 250 300 350 400 450 500 4(Best)3(High)2(Medium)1(Low) TIPHON QoS Class Delay (ms) Degradation Category (Packet Loss) 0 3 15 25 0 5 10 15 20 25 PerfectGoodMediumPoor Degradation Category % Loss Source: VON Europe’99

8. SIP-ENUM-- --- S.,L. Chou 8 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Numbering & Addressing  How to Address Calls Passing over Different Networks ? IP  PSTN --- Easier PSTN  IP --- Hard to Do at Current Stage !  Global Numbering/Addressing Scheme across PSTN and IP Networks What ? ITU-T E.164 ? E.164 Number to IP Device ENUM  Mapping E.164 Number to Domain Name  Consistent with E.164 Numbering  Country Code  Impact on IP Address Management Lack of IPv4 Address IPv6 ?

9. SIP-ENUM-- --- S.,L. Chou 9 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP Applications Enterprise VoIP Gateway VoIP Phone Residential GW Trunk GW IP PBX Softswitch Application Server Media Server ENUM 3G Softswitch VoIP Mobile Toll By Pass ITSP Basic Service Widely Deployment New Services IP/PSTN Convergence All-IP Networking 97 990205

10. SIP-ENUM-- --- S.,L. Chou 10 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 IP-PBX Trial Deployment in CCL/ITRI

11. SIP-ENUM-- --- S.,L. Chou 11 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP + WLAN + Cellular WLAN Telephony System GSM/GPRS/3G Home Enterprise Public Hot Spots VoIP Video IMPS Push-to-Talk … Home  Corporation  PWLAN/Cellular One Number, One Device Global Presence/Instant Messaging VoIP/Video

12. SIP-ENUM-- --- S.,L. Chou 12 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 IP/PSTN Convergence PSTN SIP Proxy ENUM Service System SIP Phone Gateway Softswitch Application Server Media Server SIP Telephony H.323 ENUM Servers Operator 1 Operator 2 SIP DNS IP Network

13. SIP-ENUM-- --- S.,L. Chou 13 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 VoIP Services Applications  PSTN’s (Telecomm.’s) Point of View Equip PSTN with VoIP Services Original Voice Users  For Cost Saving, No Service Enhancement Class 4/5 Switch Replacement with Softswitch  ISP’s (IP’s) Point of View Enhance Data Network with VoIP Capability Additional Voice Service to Original Data Users  Even Voice/Data Integrated Services SIP Telephony + Application/Media Servers Incentive  Low Incentive  High

14. SIP-ENUM-- --- S.,L. Chou 14 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 From H.323 to SIP

15. SIP-ENUM-- --- S.,L. Chou 15 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 H.323 for VoIP  Has Been Adopted by Vendors for Years  Almost Current VoIP Products Support H.323  Gateway  Gatekeeper  Terminal  MCU Packet Based Network N-ISDN B-ISDN H.320 Terminal H.321 Terminal H.321 Terminal H.310 terminal operating in H.321 mode GSTN H.324 Terminal H.322 Terminal Guaranteed QoS LAN Speech Terminal Speech Terminal V.70 Terminal H.323 MCU H.323 Terminal H.323 Terminal H.323 Terminal H.323 Gatekeeper H.323 Gateway Packet Based Network

16. SIP-ENUM-- --- S.,L. Chou 16 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Challenges of H.323  H.323 Was Originally Proposed for LAN Environment Limitation Being Applied for VoIP Infrastructure Applications  Architecture is Too Simple Single Gateway to Interact with PSTN/GSM Suitable for Peer to Peer Communication  Protocol is Too Complex Complicated Call Set-Up Signaling Hard to Extend  Signaling Is Not Enough Only DTMF is Specified No SS7 Signaling Capability Advanced Services are Limited  Interoperability is Still an Issue

17. SIP-ENUM-- --- S.,L. Chou 17 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Gateway Decomposition SS7 Signaling Traffic Media GW (MG) Media GW Controller (MGC) Signaling GW (SG) H.323 GW MGC: Call Control, Call Routing, Service Selection,… SG Interface with SS7 and Translate to SS7 over IP MG Dedicate for Media Translation and Transportation MGCP

18. SIP-ENUM-- --- S.,L. Chou 18 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Media Gateway Control SGCP Telcordia May ‘98 MDCP AT&T Dec ‘98 Aug ‘00 MEGACO/H.248 IETF/ITU-T Level3,... Aug ‘98 IPDC 0.12 IPDC 1.0 Sept ‘98 MGCP 1.0 IPDC: IP Device Control Protocol SGCP: Simple Gateway Control Protocol MGCP: Media Gateway Control Protocol MDCP: Media Device Control Protocol MEGACO: Media GAteway Control (IETF Working Group)

19. SIP-ENUM-- --- S.,L. Chou 19 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 MGCP/MEGACO/H.248  Client-Server Architecture  Call Agent (Media Gateway Controller) Call Control Server  Media Gateway Dedicated for Media Transmission Trunk/Access/Residential GWs  Signal Gateway SS7 Interfacing RTP Streams SS7 (ISUP) SGW SS7 (ISUP) TrunkGW TrunkGW CO IP phone Access GW/ IP-PBX/RGW IP phone MGCP MGC (CA) MGC (CA) MGCP/ MEGACO MGCP/ MEGACO

20. SIP-ENUM-- --- S.,L. Chou 20 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ISUP/MGCP/SIP Interworking SG MGC SG

21. SIP-ENUM-- --- S.,L. Chou 21 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SS7 over IP ISUP TCAP SCCP MAP MTP OSI Layers Application Presentation Session Transport Network Data Link Physical INAP SS7 Protocol Stack ISUP TCAP SCCP MAP SCN S ignaling A daptation (M3UA, IUA, …) C ommon S ignaling T ransport (SCTP) IP INAP SIGTRAN Protocol Stack

22. SIP-ENUM-- --- S.,L. Chou 22 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Internet Telecom System IN/SCP RTP Streams IP Network MGC SS7 VoIP Signaling Gateway PSTN SS7 Trunk Gateway VoIP SG Trunk Gateway SIP -T MGCP/ MEGACO SCTP Gatekeeper/Billing/Internet Messaging Authentication/Directory/... SIP+ (?) CoreBui lder 9000 Application Server SIP ITG/IP-PBX

23. SIP-ENUM-- --- S.,L. Chou 23 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Wireless System --- From GSM to GPRS GPRS External Data Network PSTN HLR SGSNGGSN Gb Gn Gi GSM PCU BSS Gateway MSC/VLR Visited MSC/VLR Always-On Wireless Packet Data Services

24. SIP-ENUM-- --- S.,L. Chou 24 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 IP Multimedia in 3G All-IP System

25. SIP-ENUM-- --- S.,L. Chou 25 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP in 3G All-IP System SGSN GGSN GPRS Backbone IP Network Alternative Access Network CSCF MGCF MGF VoIP Network PSTN/GSM Gm HSS Multimedia Sub-Core Network (VoIP) Applications & Services (OSA Platform) Gm: Interface between UE and CSCF - Over GPRS Data Bearer Service - Based on SIP (RFC 2543) Protocol - For Application Level Signaling * Register to CSCF * Call Orgination/Termination * Supplementary Services

26. SIP-ENUM-- --- S.,L. Chou 26 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP-based IP Multimedia Communication System

27. SIP-ENUM-- --- S.,L. Chou 27 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP Telephony System User Agent Client(Caller) User Agent Server(Callee) Proxy Server Redirect Server Location Server SIP Request SIP Response RTP Media Stream

28. SIP-ENUM-- --- S.,L. Chou 28 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Session Initiation Protocol  Session Initiation Protocol SIP is HTTP-like, Text-based Client-server Protocol (client-to-client is possible) To Establish, Modify and Terminate Multimedia Sessions or Calls Be able to Integrate Voice, Video and other Interactive Communication Services with Instant Messaging and Presence  Original RFC 2543 --- Feb, 1999  Newest RFCs --- July, 2002 RFC 3261 SIP: Session Initiation Protocol RFC 3262 Reliability of Provisional Response in Session Initiation Protocol (SIP) RFC 3263 Session Initiation Protocol (SIP): Location SIP Servers RFC 3264 An Offer/Answer Model with Session Description Protocol (SDP) RFC 3265 Session Initiation Protocol (SIP)-Specific Event Notification

29. SIP-ENUM-- --- S.,L. Chou 29 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP Attributes  User Agents End Systems Acting on Behalf of a User  Clients(UAC) to initiate a SIP request and servers(UAS) to receive the request and return responses  Servers Proxy Server Relay Call Signaling Redirect Server Registrar Server: User Locations Tracking (Like HLR in GSM)  Naming & Addressing SIP URL, e-mail like: user@hostuser@host Examples Sip:patrik@example.com Sip:Jackie@176.7.6.1

30. SIP-ENUM-- --- S.,L. Chou 30 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP Operation in Proxy Mode

31. SIP-ENUM-- --- S.,L. Chou 31 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP Operation in Redirect Mode

32. SIP-ENUM-- --- S.,L. Chou 32 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Protocol Format INVITE sip:pgn@example.se SIP/2.0 Via: SIP/2.0/UDP science.fiction.com From: Fingal To: Patric Call-ID: 1234567890@science.fiction.com Cseq: 1 INVITE Subject: lunch at La Empenada? Content-Type: applcation/sdp Content-Length: … v=0 o=ffl 53655765 2353687637 IN IP4 123.4.5.6 s=Chorizo c=IN IP4 science.fiction.com m=audio 5004 RTP/AVP 0 3 5 a=rtpmap:0 PCMU/8000 SIP Header Payload: MIME type (SDP)

33. SIP-ENUM-- --- S.,L. Chou 33 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP in IP Multimedia Architecture Applications SDP/SDPng HTTPSMTPSAPSIPRTSP TCP/SCTPTCP/UDPUDP RTP/ RTCP RSVPRSVP IPv4/IPv6 with Mobility, DiffServ and Multicast Common Addressing, user@domainuser@domain (URI & URL) Text-based and Encoding Format Same Request-Response Model, and Response Codes MIME for Flexible Payload DNS for Address Mapping Easy to Do Integrated Services by Combining more than One Protocols

34. SIP-ENUM-- --- S.,L. Chou 34 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP-Based Services  Internet Telephony Well-Recognized IP Telephony System  Instant Messaging Exchange of Content between Participants in Real-time  Presence Subscription to and notification of changes in the comm. State of a users Currently worked by SIMPLE WG in IETF  Click-to-Call from an Electronic Document ‘SIP as tag’ Contained in Document  Transport of MIME in SIP Signaling Reference to Web/WAP Pages, mail, pictures  Interactive Games with SIP Signaling

35. SIP-ENUM-- --- S.,L. Chou 35 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Rich Call with SIP  Before the Call Dynamic Phone Book Click-to-Talk  During Call Establishment Sending a Rich Clip, which Can be  A Picture with Call Subject, or  Special Ringing Tone  During the Call Document Sharing Information Push  During Session Tear-Down (same as Call Establishment)  After the Call Be Able to Send Instant Message

36. SIP-ENUM-- --- S.,L. Chou 36 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 SIP for IP Convergence  In 3G and NGN, the Focus Shift towards to All-IP Paradigm IP Transport, IP Mobility and VoIP (e.g. SIP) Protocol  SIP Has Been Adopted by 3GPP for Session Signaling  SIP Telephony System Has Been Well Accepted  With SIP, Service Creation is Fast and Easy IP Protocols vs. Telecom Protocol, like IN Be able to Integrate Most IP-based Services  Service Mobility and Personal Reachability By SIP and IPv6 Mobility

37. SIP-ENUM-- --- S.,L. Chou 37 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM for IP-PSTN Convergence

38. SIP-ENUM-- --- S.,L. Chou 38 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM 101  What is ENUM (RFC 2916)? Make Telephone Number Become a Domain Name in Internet  Importance of ENUM Mechanism for IP/PSTN Convergence  Global ENUM Activities IETF, ITU-T, US ENUM Form, Europe, … ENUM Trials: More Than 10 Countries  Different Kinds of ENUM Public ENUM: Future Vision Carrier ENUM: Enhance MMS/SMS Services Enterprise ENUM: Enhance Enterprise Telecomm Service

39. SIP-ENUM-- --- S.,L. Chou 39 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 What is ENUM ? ENUM Mechanism E.164 Number Domain Name System (DNS) URI(Service@Host) ENUM is a Mechanism to Translate an E.164 Number into A List of URI (Service@Host)Service@Host So that An IP User Can be Accessed by E.164 Number. Problem: How to Address (or Locate) a User in IP Telephony World or PSTN/VoIP Integrated Network ?

40. SIP-ENUM-- --- S.,L. Chou 40 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM Domain

41. SIP-ENUM-- --- S.,L. Chou 41 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM DNS Hierarchy 2.6.8.8.e164.arpa -> ns1.t1a.com; ns2.t1a.com 6.6.8.8.e164.arpa -> ns1.t1b.com; ns2.t1b.com 4.3.2.1.4.9.3.2.2.6.8.8.e164.arpa -> NAPTR RRs (ldap URL) LDAP DB... Tier 1 Tier 2 (Designated by the end user) 4.3.2.1.4.9.3.2.2.6.8.8.e164.arpa -> ns1.t2.biz; ns2.t2.biz Tier 3 (Depending on the application) 6.8.8.e164.arpa -> ns1.t1.com ns2.t1.com Tier 0 (RIPE) ns1.t1.com/ns2.t1.com... 4.3.2.1.8.9.2.6.6.8.8.e164.arpa -> ns1.t2.org; ns2.t2.org ns1.t1b.com/ns2.t1b.com ns1.t1a.com/ns2.t1a.com ns1.t2.biz/ns2.t2.biz ldap URL Source: James Yum, Neustar.arpa.

42. SIP-ENUM-- --- S.,L. Chou 42 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM Scenario IP Network Softswitch SIP Proxy IAD ENUM Server E-Mail Server 1 5 Dial:03-5915616 2 SIP Phone 3 3 0910961527 4 1.User Dial Tel. No 2.ENUM Query, get 3 URIs 3.Make SIP Call, No Answer 4.Make Mobile Call, Fail 5.Connect to E-Mail DNS $ORIGIN 6.1.6.5.1.9.5.3.6.8.8.e164.arpa. IN NAPTR 100 10 “u” “sip+E2U” “!^.*$!sip:slchou@itri-sip-proxy.org.tw!” IN NAPTR 102 10 “u” “tel+E2U” “!^.*$!tel:+886910961527!” IN NAPTR 102 10 “u” “mailto+E2U” “!^.*$!mailto:slchou@itri.org.tw!” $ORIGIN 6.1.6.5.1.9.5.3.6.8.8.e164.arpa. IN NAPTR 100 10 “u” “sip+E2U” “!^.*$!sip:slchou@itri-sip-proxy.org.tw!” IN NAPTR 102 10 “u” “tel+E2U” “!^.*$!tel:+886910961527!” IN NAPTR 102 10 “u” “mailto+E2U” “!^.*$!mailto:slchou@itri.org.tw!” Media Gateway Signal Gateway E.164 number +886-3-5915616 SIP URI Mobile phone number Email address Enum Record

43. SIP-ENUM-- --- S.,L. Chou 43 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 ENUM Scenario (cont.) 1.User Make Call to E.164 Number: 03-5915616 2.Softswitch Translates the E.164 Number to Query Input to ENUM Server: 6.1.6.5.1.9.5.3.6.8.8.e164.arpa and gets a list of URIs returned 3.The Softswitch Processes the 1 st URI Record, a.Query DNS to get the IP Address of Host: itri-sip-proxy.org.tw b.Make SIP Call to SIP Phone of slchou through SIP Proxy c.SIP Phone Does not Answer 4.The Softswitch Processes the 2 nd URI Record, a.Make PSTN Call Through Gateway to 0910961527 b.0910961527 Does not Answer 5.The Softswitch Processes the 3rd URI Record, a.Query DNS to get the IP Address of Host: itri.org.tw b.Connect the Caller E-Mail Server SMTP Protocol c.Caller Leave the E-Mail Message

44. SIP-ENUM-- --- S.,L. Chou 44 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Tier-0 Top Level Domain (TLD)  The Choice of Common Designated Domain fir ENUM Tier-0 is Undecided and is Proving Controversial ARPA as ENUM TLD is Controlled by IETF and Operated by RIPE-NCC  US and some other countries, ISOC/IAB/IETF Support IETF Conclusion  European Union, France and Germany Proposed ITU-TSB as the Operator for ENUM  China, France, Germany, Syria and Spain Objected to ARPA as TLD for political reason  to reinforce the infrastructure of Internet governance E.A-ENUM Recommendation  “Principle and procedures for the administration of E.164 Country codes for registration into the Domain Name System”  TLD is open  ITU-TSB is the ENUM Tier-0 Administrator

45. SIP-ENUM-- --- S.,L. Chou 45 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Option of ENUM Structure Tier1 Registry Tier2 Registry ROOT Registrar Registrant Authentication and Validation Entity ASP Tier2 Registry Tier0 E164.tw ENUM Number Assignment Entity

46. SIP-ENUM-- --- S.,L. Chou 46 工業技術研究院 電腦與通訊工業研究所 Industrial Technology Research Institute Computer & Communications Research Laboratories 11/21/00 Conclusions  H.323 Will Evolved to MEGACO and SIP  SIP-based IP Multimedia Service will Dominate  SIP is the Key for IP/PSTN Convergence  ENUM is An Important Enabling Technology to Speed-up IP/PSTN Convergence  SIP-based Telephony Begin to Boom