ENUM Theory, Implementation, VoIP and Routing SolutionsGary Richenaker


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ENUM Theory, Implementation, VoIP and Routing SolutionsGary Richenaker

  1. 1. ENUM Theory, Implementation, VoIP and Routing Solutions Prepared for: Contact: Gary Richenaker Chief Architect Telcordia Technologies Interconnection Solutions 732 699.3264 grichena@telcordia.com Copyright © 2007 Telcordia Technologies. All Rights Reserved. TELCORDIA TECHNOLOGIES, INC. RESTRICTED ACCESS This document contains proprietary information that shall be distributed, routed or made available only within Telcordia Technologies, except with written permission of Telcordia Technologies.
  2. 2. ENUM Theory and Implementation § Operator Business Challenges § ENUM Overview § ENUM Sample Use Cases § How Does ENUM Work? § ENUM Architecture § Implementation Considerations § Implementation Approaches & Worldwide Deployment Status 2
  3. 3. Challenges of Converged Services on User Identification § Telephone numbers remain a key identification mechanism for users to find each other § With convergence, there are more ways to identify a user – email address, URL, IM buddy name • Can a user reaching another user with a Telephone Number for these converged services? • How can an Operator find an IP route to the destination user served by another Operator using a Telephone Number? 3
  4. 4. ENUM = Electronic Telephone Number Mapping - Key to Deliver Converged Services ENUM Internet domain Directory name addresses Domain Name Service (DNS) Enabled Applications • VoIP E.164 Numbers: Internet • Unified messaging One number • Instant messaging mapped to many • IP fax applications or • Personal web pages services Telephony Networks 4
  5. 5. What Is ENUM? § ENUM is one of the enablers of circuit-switched & packet network convergence § Defined by Internet Engineering Task Force (IETF) § Translates an E.164 number into Internet domain names § ENUM is about new service creation § Allows use of telephone numbers in various communication media, e.g., e-mail, VoIP § Can easily facilitate penetration of applications into mass market § Defines use of DNS resource records to find optional: § E-mail addresses § Voice over IP SIP / H.323 servers § Voice mail servers § Fax machines 5
  6. 6. ENUM - Sample Use Case IP-IP Service Interconnection (e.g., VoIP) TN A calls TN C Softswitch DNS/ A ENUM 2 PSTN 3 IP A 1 4 Softswitch B C TN = Telephone Number 6
  7. 7. ENUM - Sample Use Case IP-PSTN Service Interconnection TN A calls TN D Softswitch DNS/ A ENUM D PSTN IP A Softswitch B 7
  8. 8. ENUM - Sample Use Case PSTN-IP Service Interconnection TN D calls TN A Softswitch DNS/ A ENUM D A PSTN IP A Softswitch B 8
  9. 9. ENUM – Sample Use Case WAP Application Access using Telephone Numbers WAP = Wireless Application Protocol DNS/ 1 ENUM IP WAP 2 WAP Gateway 3 Application Example: Verisign’s WebNum Trial Delta Airlines 18002211212 www.delta-air.com/servlet/wireless Northwest Airlines 18002252525 wireless.nwa.com Charles Schwab 18775238434 pb.schwab.com MSN Entertainment 18004269400 mobile.msn.com/hdml/sports.asp E*Trade 1800ETRADE1 www.etrade.com Ebay 14085587400 catalyst.2roam.com/www.ebay.com 9
  10. 10. ENUM – Sample Use Case Directory Assistance for Other Identifiers Using TN 1 2 DNS/ ENUM 4 IP 3 PSTN 10
  11. 11. How Does ENUM Work? Simple ENUM Example 1) Takes a phone number +1 732 699 3264 2) Turns into a domain name 3) Ask the DNS mailto:grichena@telcordia.com 4) Returns a list of URIs sip:gary.richenaker@carrier.net URI: Uniform Resource Identifier 11
  12. 12. How Does ENUM Work? Simple ENUM Example DNS Server Response Query sip:gary.richenaker@carrier.net Call Setup Dial sip:gary.richenaker@carrier.net +17326993264 Gateway SIP Server 12
  13. 13. How to Implement ENUM? Architectural Considerations § ITU & ISOC working on global-tree ENUM implementation § Why is a unique top-level domain used in ENUM? § I have phone number: +1 973 829 4305 § I can choose between a.com and b.com § I select b.com and get the DNS domain § If someone who only knows my phone number wants to contact me how will he/she know I have my data in b.com & not a.com? § ITU/ISOC global-tree is a top rooted, global DNS ENUM implementation 13
  14. 14. How to Implement ENUM? Tiered Architecture Approach Registry Directs DNS query to country’s Tier-1 registry(ies). Tier-0 NS record* provided for each Tier-1 registry International-RIPE-NCC & ITU-TSB CC 1 CC 44 National Directs DNS query to customer’s Tier-2 Registry Registry providers. NS record provided for each Tier-1 Tier-1 subscriber’s telephone number Stores list of service-specific internet addresses in of Provider URI’s in a DNS resource record called NAPTR for each Tier-2 subscriber. Returns the full list of Internet addresses associated with the E.164 number being queried. *An NS record is an authoritative name server DNS record used to delegate to subordinates 14
  15. 15. Sample ENUM Architecture Root arpa, com, edu, org, net International Tier 0 e164.arpa National Tier 1 1.e164.arpa (country code) Registry Registrars 1…n Tier 2 Registry NAPTR Record users sip:gary.richenaker@sipes.se mailto:grichena@telcordia.com 15
  16. 16. Tier 0 Public ENUM Delegations as of October 1, 2007 1 NANP 40 Romania 66 Thailand 246 Diego Garcia 41 Switzerland 81 Japan 247 Ascension 420 Czech Republic 82 Korea 290 Saint Helena 421 Slovak Republic 84 Vietnam 30 Greece 423 Liechtenstein 86 China 31 Netherlands 43 Austria 971 UAE 33 France 44 UK 350 Gilbraltar 46 Sweden 878 10 VISIONng 353 Ireland 47 Norway 882 34 Global Networks 354 Iceland 48 Poland Switzerland AG 358 Finland 49 Germany French Territories 359 Bulgaria 55 Brazil 262, 508, 590, 594, 596 36 Hungary 61 Australia 374 Armenia 62 Indonesia 39 Italy 63 Philippines 65 Singapore 16
  17. 17. Sample Flow to Provision ENUM Records Domain Name System Validation of telephone ENUM Tier-1 pointers to name servers w/ number X ENUM record for telephone number X Telephone 2 Number X End-user 3 ENUM Tier-2 ENUM NAPTR record for registrant Registrar Telephone Number X 5 Service Calling 1 application 4 Party ? 6 LDAP ENUM Record database if needed Protocol Service Address SIP sip:grichenaker@telcordia.com Legend: SMTP smtp:grichena@telcordia.com Provisioning flow TEL tel:+17326993264 steps 1, 2, 3 HTTP http://telcordia.com Resolution flow TEL tel:+18005551234 steps 4, 5, 6 17
  18. 18. ENUM Implementation Considerations: Privacy § Registrant opt-in choice is central to ENUM operation § Optional participation in ENUM § Registrants choose exact information included in naming authority pointer records (NAPTR) & preferences for how information is used § Registrants choosing ENUM should choose how information disclosed is used § Key for privacy protection is using personally identifiable information only how it was intended § Do existing regulations protect privacy rights relative to ENUM? 18
  19. 19. ENUM Implementation Approaches and Worldwide Deployment Status Three ENUM Implementation Approaches: § Public ENUM (End User ENUM) § Carrier ENUM (Infrastructure ENUM) § Private ENUM 19
  20. 20. Public ENUM § Also known as End User ENUM § Records entered by end users to associate Telephone Numbers with the URIs of their devices § Implementation architecture widely discussed in standards bodies and industry forums § Key concerns on data availability, validity and privacy 20
  21. 21. Public ENUM Status Countries that have trialed Public ENUM § Austria § Netherlands § Finland § Poland § France § Sweden § Germany § South Korea § Ireland § Switzerland § Japan § UK § US 21
  22. 22. Public ENUM Observations § Based on the trials the following observations can be made § ENUM is viewed as a potential enabler for future services and therefore has general regulatory support § Privacy and data security issues are viewed as critical § The approach towards validation/authentication varies widely, from very secure to almost non-existent § The implementation approach and interface requirements also vary widely § There is currently no killer application for the initial launch, but there is a strong focus on VoIP § There are differing views on the importance and potential role of incumbent telco § Regulatory issues are important but are not THE key factor in the rollout of ENUM services 22
  23. 23. Making Public ENUM Actually Work § How will carriers and enterprises provision ENUM? § In order for ENUM to work, Carriers and Enterprises will have to exchange data on their TN-to-URI translations § Carrier Customer Management Systems will have to learn how to provision ENUM § What is the business model? § What will be the model for how much the Registrar, Tier 1, and Tier 2 ENUM providers get paid? § What is the end user willingness to pay? § Will there be Regulatory policies relating to security and privacy? 23
  24. 24. ENUM Implementation Approaches Party to Data TN-URI Deployment control data Accessibility Mapping Status End user (opt- Public Full end-user Country-wide trials in) (ENUM DNS entries TN to end- e.g., CC1 ENUM Public may exist only if the user URI LLC, with limited ENUM number assignee commercial opts in) offerings Carrier/ Infra ENUM Private ENUM 24
  25. 25. Carrier ENUM: Database in the Sky Routes Routes SP1 creates SP2 creates DNS records in DNS records in Carrier ENUM 2 3 Carrier ENUM DNS ENUM Query Routes Routes Routes Routes DNS ENUM 4 Query Access 5 Administrator CSCF CSCF 1 Network Administrator 6 SP1 SP2 SIP Invite Local Local Local Local Routes Routes Routes Routes MGW MGW 25
  26. 26. Status of Carrier ENUM § Requirements work on draft RFCs & other related standards are still progressing § No trial using a Carrier/Infrastructure ENUM approach § Not clear carriers or operators would place their numbers & entry points to their network in publicly accessible DNS tree 26
  27. 27. ENUM Implementation Approaches Party to Data TN-URI Deployment control data Accessibility Mapping Status End user (opt- Public Full end-user Country-wide trials in) (ENUM DNS entries TN to end- e.g., CC1 ENUM Public may exist only if the user URI LLC, with limited ENUM number assignee commercial opts in) offerings Carrier/ Operator Public Full End User Still being defined Infra TN - Operator by Industry ENUM Gateway URI (End user info not disclosed) Private ENUM 27
  28. 28. Private ENUM § Private ENUM is one or more technologies (including DNS) permitting service providers to exchange TN to URI data privately & securely § Use any mutually agreed upon domain § Private ENUM is assumed authoritative for all endpoints for which service providers choose to exchange data (no need to opt out) § Private ENUM actually means private; data not accessible via general Internet. Current uses include: § Wireless carriers for MMS SMS routing § Federations, e.g., X-Connect and Stealth § MSO interconnection (Cable Labs RFI) 28
  29. 29. Private ENUM: Federation ENUM Database Carrier 1 Carrier 3 Carrier 2 Carrier 4 § Carriers optimize VoIP sessions by routing directly between carriers § Private, secure shared database within “Federation” 29
  30. 30. Service Interconnection Registry: Example Private ENUM Implementation LDC PSTN PSTN PSTN Network Network Network STP STP Service Provider Service Provider Service B A PSTN Interconnection PSTN Gateways Registry Gateways IP Network IP Any Network IP Network SIP SIP Proxies Proxies IP Device Associates TNs or number blocks IP Device with Internet addresses (URIs) 30
  31. 31. ENUM Implementation Approaches Party to Data TN-URI Deployment control data Accessibility Mapping Status End user (opt- Public Full end-user Country-wide trials in) (ENUM DNS TN to end-user e.g., CC1 ENUM Public entries may exist URI LLC, with limited ENUM only if the number commercial assignee opts in) offerings Carrier/ Operator Public Full End User Still being defined Infra TN - Operator by Industry ENUM Gateway URI (End user info not disclosed) Private Operator Authorized Full End User Deployed ENUM Parties TN - Operator Gateway URI 31
  32. 32. Reality: Multiple Registries Will Co-Exist Registry SP3 Provider 1 Administrator Registry Registry SP2 Registry SP4 Provider N Registry Registry Administrator SP1 Other SP Other SP SP1 Routing Routing SP1 Registry Registry Routing Data Data Routing Data Data Administrator Public SP5 ENUM Registry Registry CSCF End User 32
  33. 33. However, ENUM Does NOT Solve Address All Service Interconnection Challenges… § ENUM is a protocol § Simple concept: use DNS to resolve address based on telephone number § ENUM provides destination domain § BUT it does not address end-to-end service delivery issues § What QoS rules apply? § SLA with the terminating carrier? § What protocol/variations are used § SIP vs. H323 § G711? § What route to take? § Least cost route? § Different rates depending on the carrier selected? § What security policy/keys are needed? 33
  34. 34. Summary § ENUM is here now – start planning how to deploy as part of VoIP interconnection planning § Different flavors of ENUM will co-exist and inter-work, but traditional carriers will likely gravitate to Carrier and Private ENUM implementations § Key ENUM Success Requirements Include: § Carrier-grade, secure system § Standards Compliance (e.g., ENUM, SIP, etc.) § Interoperability with other registries § Portability, PSTN integration § Extensible to other IP services § IMS compatibility and interoperability § Select a solution architecture that is robust and flexible enough to support your VoIP/IP services strategy 34
  35. 35. When I’m online, I want text to my mobile to come up in Messenger … and I want to click to reply. That’d be cool. 35
  36. 36. I want to purchase music from the television, and send it to my mobile. Or store on my music library.. 36
  37. 37. When we’re watching a movie,we want to see who is calling when the phone rings. on the television. 37
  38. 38. Great goal! I’ll send that as a message to my friends 38
  39. 39. Ah, What a match. 39
  40. 40. I’m on the train. I saw the score Joe Gonzales Joe Gonzales change? 732-699-5555 732-699-5555 Was it a good goal? Are you watching Are you watching the game? the game? Joe, Hi, I sure am watching the Joe, that was a great match! goal, I’ll send it to your cell phone 40
  41. 41. Pretty neat. How’s our fantasy team doing? Replay Replay Live Live Let me check. 41
  42. 42. That’s great. See you tomorrow at our match. Bye. Final StandingsTSN R Manager 1 Team 1855 k 2 Bicycle kickers P 1775 Woodersen 0 3 Basso F.C. 1768 0 4 Ginas Guys 1728 0 5 MaxMOJO 1722 0 6 blind luck 1716 0 7 Valderrama 1716 0 8 Soccer10 1703 0 9 Crew Brew 1697 5 1 Richton Park 1695 0 1 0 Marshall Plan Fire 1688 0 1 Section One 1684 0 1 2 Wazirds 1682 5 1 3 Etcheverry 1680 5 1 4 McBride 1677 0 1 5 Pele is here!!! 1675 0 6 0 With that goal, they moved up one spot. 42
  43. 43. Now, back to this game! 43
  44. 44. What will it take to achieve the vision? § A Broadband, IP Infrastructure § Convergent Services and Customer Bundles § Good Marketing and Communications § Rapid Introduction of Innovative New Services § Network and Service Quality and Security § Cost Efficient Operation § Business Transformation to a Service-Centric Operation and Customer-Centric Organization 44
  45. 45. The Market Wants . . EASE-OF-USE . AVAILABILITY § Transparent to Users § … of services § Same Services / Same User Experience § In-building § At home § Network-Resident User Profile – § On the road ensures seamless services across devices USER EXPERIENCE AFFORDABILITY § Quality § Best Price / Performance (for § Consistency consumers) § Personalized § Best Cost / Performance (for operators) INTERWORKING § Take Advantage of Embedded Home / Enterprise Networks § Circuit - Packet § Hand-offs DISTRIBUTED . . . § Virtual Home Environment § Networks § Fast & Easy Authorization § Operations (ownership) § Flexible Charging / Billing § Services § Data For the last 100 years it was all about the network … Now it’s all about the Customer Experience enabled by the network. 45
  46. 46. Put All This Together and You Get Converged Communications Convergence means “Integration” & “Simplicity ”: • Integrating Services: voice, data, video • Integrating Networks: fixed, Fixed Wireless and mobile • Unifying services across networks and enterprises • Universal devices that are network-independent The Power of Convergence: • Convergence will allow operators to cross traditional boundaries and leverage their entire business and infrastructure to gain an “unfair advantage”. • Convergence will reduce operational and capital expenditures • Convergence allows sharing of service enablers and applications that will open their networks and allow others to pay for and provide services that will differentiate your business ! 46
  47. 47. Data Points on Sample Services – Growing Subscription on Converged $190.0B Services $101.4M $24.2B $61.0B $39.1M $7.0B 2004 2009 2004 2008 2004 2009 Source: In-Stat 2005 Source: Gartner Group 2004-2005 Source: Strategy Analytics 2005 Worldwide Worldwide Worldwide Push To Talk Users VoIP Services Revenues Mobile Data Revenues More converged and bundled services are being introduced and adopted….. 47
  48. 48. Fast Response to Market Requires Operators to be Agile – Silo Approach No Longer Works Past Future Wireless Wireline Voice Voice Video Data Guides / Directories Wireless/Wireline Operator Services Internet Access Operator Virus Operator Services Entertainment CPE Applications Services Scanning Video Voice Video Directory Directory Guide Email CPE CPE Content Routing Vertical Vertical IP Multimedia Subsystem (IMS) Features (Middle Layer) Features Transport Transport Transport Internet Protocol (IP) Transport Broadband Connection 48
  49. 49. Impacts of VoIP and Converged Services on Numbering § Emergence of VoIP and Converged Services § Impacts on Operator Infrastructure § Regulatory Implications § Impacts on Numbering and Number Portability § Impacts on Interconnection 49
  50. 50. Further Impacts on Operator Infrastructure • Security • Service quality and QoS • Mandated services (E911, • Reliability CALEA, LNP) Ser ed Qu vice • Traffic engineering • Advanced service offerings vanc and a • Customer experience • Feature interactions Ad ices ns Su lity rv io ppo • Service integration and reuse Se eract rt Int Call Agent Databases ent oym e th Applications Infr • Scalability OS ructu Wide porting • Work center of the future ast • Evolution S/B • Service fulfillment Depl IP IP • Service assurance • CO consolidation SS e Sup • Network traffic management • Backbone IP r • Training network planning Interconnection and Interoperability Testing and interoperability • Interconnection architecture • Conformance testing • Addressing & routing • Interoperable across technologies • Interconnection agreements • Across supplier implementations • Billing and settlements 50
  51. 51. Converged Services Also Change the Game on Regulatory Mandates § Emergency services – location information § Calling Line Identity presentation (and restriction) § Legal interception § Number portability § Quality of Service § Carrier selection and pre-selection § Directory services § Tariff legal requirements § Net Neutrality § Emerging mandates on selected converged services; IP TV 51
  52. 52. Other Regulatory Concerns On VoIP § PC-to-PC VoIP services (e.g., basic Skype) are generally not considered telecom services as no national resources (numbers) are used § Regulators are more concerned with substitution of traditional PSTN services like PC-to-Phone or Phone-to-PC VoIP applications (e.g., Skype-Out and Skype-In services, Vonage, Yahoo!BB, etc) § Regulators are looking at the economic and social issues surrounding VoIP § In numerous countries incumbents have significant influence over regulatory agency. 52
  53. 53. Impacts of Converged Services on Numbering § Numbering should be technology neutral § Choice of number ranges interacts with operators commercial objectives § Possible number ranges: § Geographic § Mobile § Personal § Corporate § New § Shared cost & premium rate services excluded from formal discussion at this time 53
  54. 54. Converged Services and Number Allocation § Numbering assignments for converged services (e.g., VoIP) § Assess the implications of the choice of different numbering schemes for interoperability and interconnection between PSTN and IP networks § Understanding the legislative and regulatory issues around VoIP and the implications for number portability § Nomadicity as it relates to number portability 54
  55. 55. Impacts of Converged Services On Interconnection § Converged Services mostly likely require end-to-end IP transport to enable value-added features § Today, most IP-enabled services are routed over PSTN when the session needs to be terminated in another Operator’s network § Implications § Inability to deliver enhanced services § Use telephony settlement model which has evolved over a century and has a much difficult structure and traffic pattern § The US has models based on interstate, intrastate, and local § The European model is more straightforward § Strong need for direct service interconnection over IP 55
  56. 56. The new “Peering Model” and the Impact on Interconnection Transit LEC LEC Provider $ $ $ $ Termination Earnings Long Distance Costs Termination Costs Routing Registries LEC LEC Settlement Free or low Termination Cost $ 56
  57. 57. IP Service Interconnection or “Peering” Impacts § Traditional carriers are moving to VoIP and other IP-enabled services to met competition and customer demand § With IP service interconnection, carriers can more efficiently interconnect an settle traffic directly among themselves § Consequently, IP transport will drive the cost of transport out of termination rates § Minute and distance sensitive pricing will give way to port and signaling transport fees 57
  58. 58. How are IP Service Sessions Routed? § ENUM will become the global standard to enable IP service interconnection § Address-of-record URI (Uniform Resource Identifier) § Identity for user § Address easily remembered. § Used in To and From headers of SIP messages. § Not associated with any endpoint. § Hostname is usually a domain. § e.g. sip:joe.bloggs@example.org (just like ‘mailto:user@host’) § Routed by DNS lookup on example.org § Contact address URI § A URI specific to a particular device rather than a user. § Hostname is an IP address, or refers to a particular device. § Appears in contact header & sometimes request-URI of SIP messages. § e.g. sip:joe.bloggs@;transport=tcp § Routed to directly 58
  59. 59. SIP-Based VoIP Example Other Network Gateway/ ENUM Border Controller IP E.164 Routing Network (e.g. ENUM) - Converts E.164 to URI Domain Name Service (e.g. DNS) Router - Converts URI/URL into IP address Inter-network IP Routing (e.g. BGP, etc) - Finds path between two IP addresses in different DNS networks SIP Intra-network IP Routing Proxies (e.g. OSPF, RIP, etc) - Finds path between two IP IP Device addresses in same sub- sip:gary@telcordia.com => network => sip:gary@telcordia.com IP Device 59
  60. 60. Example Implementation: Service Interconnection Registry LDC LDC PSTN PSTN Network PSTN Network Network STP STP Operator A Service Operator B PSTN Interconnection PSTN Gateways Registry Gateways IP Network IP Network Any IP Network SIP SIP Proxies Associates E.164 TNs with Internet Proxies addresses (URIs) based on Operator- IP Device defined business relationships IP Device 60
  61. 61. Impacts of Converged Services on Number Portability Since Converged Services will likely leverage ENUM to use Telephone Numbers as the key user identifier, what is the impact on Number Portability? § Will ENUM replace portability? § Is ENUM the ultimate technical solution to portability? § Does ENUM signify the end of portability? 61
  62. 62. Fixed Mobile Convergence and the Future of Porting § Number Portability not an issue when numbering plan does not distinguish between landline and mobile telephone numbers § In countries where numbers are specially allocated to distinguish the difference between mobile and landline traffic does the FMC require: § Numbering Plans to be changed? § Tariffs restructured § Customer education 62
  63. 63. Number Portability Challenges in an IP Environment § PSTN/TDM & IP networks will co-exist § Synchronization of ported information is required § Push vs. pull § Push – number portability database drives deletion of old registration & creation of new registration § Pull - ported to carrier responsible for change in number portability environment § In some countries no central number portability database exists 63
  64. 64. Number Portability in a PSTN and IP Environment – Sample Architecture Number Portability Clearinghouse IP Master Reference Routing Database Server Operator Operator B A PSTN PSTN PSTN PSTN Network Device Network Device STP STP PSTN PSTN Gateway Gateway ENUM ENUM ENUM Edge Master Edge Server ENUM/ VoIP/IP VoIP/IP ENUM/ Edge Device Device Edge 64
  65. 65. Summary § Converged services are here now § Regulators need to re-examine existing mandates in face of these innovative services § Operators require a flexible infrastructure such as IMS to quickly adapt to market conditions § Converged Services require IP interconnection among Operators – calling for a new approach to consider architecture implementation and settlement model § Number portability is here to stay – implementation will need to adapt to converged services needs 65