Apr05 VeriSign VoIP Portability Presentation
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Apr05 VeriSign VoIP Portability Presentation






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  • A mechanism to map … DNS based technology standard that has been approved by a working group of the IETF Translates Telephone Number to Multiple Service Addresses Uses the E.164 telephone number format to create a domain name Service Addresses (Email address, cell phone number, etc.) are stored in NAPTR records

Apr05 VeriSign VoIP Portability Presentation Presentation Transcript

  • 1. VoIP and Number Portability: Perceived v. Real Problems Tom Kershaw Vice President, VoIP VeriSign
  • 2. Agenda
    • Background
    • Circuit Switched Number Portability
    • Addressing and Portability on the Internet
    • Addressing and Portability for Wireless Data
    • A Parallel: H.323 and SIP
    • Key Portability Issues Today
    • Portability Architectures for VoIP
    • Portability Architectures for MMS
    • Recommendations, Bold Statements, Misc. Controversy
  • 3. Portability and the PSTN
    • Portability is based on regulatory mandate – Communications Act of 1996
    • Technical Approach is based on “PSTN” concepts such as:
    • Rate centers
    • LATAs
    • Lines
    • Hence, the LRN
    • Mobile has followed this model in portability and roaming, which uses TLDNs in much the same way as LRNs
    • LRNs do little more than tell the network what trunk group to use to get to the subscriber
    • What if you don’t have trunk groups, rate centers and geography?
  • 4. Portability and the Internet
    • Internet addressing introduces clear separation between Name Space and “Address”
    • Users are identified by URLs and Domain Names
    • Hence, the DNS constellations that provides root addressing for the Internet:
    • Tree-based
    • Highly resilient
    • Segmented Address Structures:
    tomkershaw verisign com @ . Address space controlled and administered by the name owner – you can have any unique address within this domain Address space administered by Registrars; any unique address can be registered within each TLD Administered by the industry/go-vernment
  • 5. Portability and the Internet
    • Namespace on the Internet maps to a network address ie [email_address] to
    • Names are segmented:
    • If I want to change my name – [email_address] , I have three choices:
    • Change the TLD ie [email_address] , assuming it is available
    • Change the domain to a new owner/name ie [email_address]
    • I can “port” my namespace into a new domain, assuming it’s available in that domain, but “tomkershaw” is not globally unique.
    • Address space is assumed to be infinite.
    • Names are fully geographic, Addresses Change Dynamically
  • 6. Portability and ENUM Service Application DNS +1 703-948-3345 To port this number, I can map the LRN to a SIP URI/:mailto:, or….. Set of NAPTR RRs Change the domain space in the routing record….. ENUM uses DNS to resolve internet namespaces for VoIP page:18005551234 Pager http://insite.VeriSign.com HTTP tel:+17039483345 TEL smtp:tkershaw@VeriSign.com SMTP sip:tkershaw@VeriSign.com SIP Service Address Protocol 1 3 2
  • 7. The Fork in the Road PSTN VoIP Path 1: Adapt current PSTN system to IP Path 2: Create an Entire New System Optimized for IP
  • 8. The Fork in the Road PSTN VoIP H.323 SIP
    • Quickest path to market
    • Non-Disruptive
    • Phased Migration
    • Expensive
    • Difficult to Integrate with IP
    • “ Voice is special….”
    • Slower to market
    • Built to last – not a corner cutter
    • Lacks features of original for some time
    • Wins in the End
  • 9. Portability Scenarios for VoIP
  • 10. Scenarios for Number Portability
    • 1) PSTN to PSTN (we have this sorted out)
    • 2) PSTN to IP
    • 3) IP to PSTN
    • 4) IP to IP
    • 5) MMS to MMS (MMSC to Handset)
    Bold Statement #1: Scenario 2 is the most important issue for VoIP operators today Bold Statement #2: Scenario #5 is the most important issue for mobile operators today Don’t Mix the Two Up
  • 11. Exec Summary (the Punch Line)
    • Currently, the biggest issue for VoIP Portability is introducing geographic portability
    • All other issues are minor in comparison
    • This must be addressed by the industry for VoIP to take off
    • Lack of geographic portability seriously hampers voip and also means most voip operators will not support portability at all
    • Until this is solved, other discussions are moot
    • The NPAC should be used for calls to or from the PSTN
    • IP addressing mechanisms such as ENUM and private trees should be used for IP to IP
    • I and P are the two most important letters in VoIP
    • Number portability should be implemented as a change to a resource record in ENUM/Location Server
  • 12. Key Points
    • Current industry discussions on “Implementing Portability for VoIP” have nothing to do with VoIP
    • VoIP operators did not ask for this
    • VoIP operators don’t benefit
    • VoIP operators need geographic portability, not URIs in the NPAC
    • The Real driver for these initiatives is MMS
    • When an MMS is received by an originating MMSC, it needs to find the terminating MMSC
    • In non-ported case, number is mapped to a carrier (easy)
    • In ported case, the LRN needs to map to a mailto: address
    • This is a very REAL problem that needs to be solved
  • 13. Geography and VoIP
    • VoIP separates the access network from the address
    • Access network can physically be anywhere; if you are on the network you are addressable
    • Similar structure to mobile – needs to have similar functionality
    • With recent FCC rulings, structure of telephone addressing will change
    • Rate Centers, City Codes, and NPAs will cease to be relevant
    • City Codes already losing relevance
    • DIDs will be available on demand, from anywhere, to anyone
    • Potential for anarchy……
    • …..but that’s how the Internet works
  • 14. My “Address” in VoIP Home (VA) Cable modem My Phone Numbers: 703-576-3287 650-834-8986 248-232-9534 214-989-4587 Friend (Dallas) Office (Mt. View) Family (Detroit) Local (VA) My Service Provider (Hawaii) IP Network My URIs tom@verisign.com [email_address] [email_address]
  • 15. The Geographic Portability Problem 1) Subscriber living in Washington DC (202-222-1234) ports her number to IPCarrier; also buys a second line with phone number 415 because her son has moved to San Francisco 2) Calls from PSTN to 202-222-1234 are “local” under tarifing rules 3) Subscriber moves across the river to Virginia; changes DSL provider but keeps VoIP provider and same phone numbers 4) Subscriber is offered better deal by a mobile operator that combines fixed and mobile into one package 5) Subscriber: Can’t port original number to new operator unless it has IMTs in the same rate center as 202-222-xxxx Can only port 408 number to a new carrier she does not even know
  • 16. Portability and VoIP to VoIP
    • When there are 10 million VoIP lines in North America, ¼% (.0025) of calls will be VoIP to VoIP
    • One of the big concerns of VoIP operators is reducing network round trips
    • Most peering architectures will map a phone number to:
    • A URI
    • An IP Address (typically of a proxy or border element)
    • The IP query will take place before a call is sent to the PSTN
    • The IP query may call out to an LNP resource
    • or the owner of the number will be up-to-date without querying the NPAC data
    • If a number is VoIP to VoIP, why call out to two databases when you can do portability and addressing in one?
  • 17. Simple Peering Architecture PSTN Media Gateway Call Agent Directory SIP/ENUM Service Broker Inter-Carrier Settlement (??) Subscriber Portal ASP Domain Applications/Services Operator A Call Agent CMTS Call Agent DSLAM Enterprise B IP Core Border Element Border Element
  • 18. An IP-to-IP Addressing Flow SIP Redirect Engine ENUM/DNS Interface to CCE External Callouts (SIP or ENUM) Number Analysis and Normalization (e.164 or URL) TN Discovery TN Exists? Yes= BE RouteList External Callout Engine *LNP *CNAM *Carrier Select (ENUM or SIP) Route Engine TN To BE Route List Proportional Route Splay Route ToD/DoW Engine Class 4 Route Default (Trunk Group, PSTN Ctvty) Route Propagation: TGREP/TRIP/Manual Provisioning Port the number here Or call out to an external directory
  • 19. Addressing in VoIP: The Internet Way Tier 1 ENUM Or Private Peering Location Server/Registrar Tier 2 ENUM Call Control Call Control Call Control Call Control
      • IN NAPTR 10 10 "u" "E2U+sip" “!^.*$!sip:tkershaw@verisign.com!”
      • Ported to
      • IN NAPTR 10 10 "u" “E2U+mailto" “!^.*$!mailto:tkershaw@sprint.com
    Misc. IP Network
  • 20. Porting in an ENUM Environment ENUM DNS Portability Request [email_address] ; [email_address] RRP | EPP Domain changed; Number “ported” DNS/ENUM Resolver Interface In : Out : NAPTR RRs ENUM is a standard translation mechanism defined by the IETF that uses DNS to convert an E.164 telephone number into a set of addresses. page:18009483258 Page http://www.VeriSign.com HTTP tel: +1 703 948 3258 TEL Smtp:tkershaw@VeriSign.com SMTP sip:tkershaw@VeriSign.com SIP Service Address (NAPTR RRs) Protocol fax: +1703 421 8233 Fax
  • 21. Extending the Model: Whois for VoIP (IRIS) DNS Location Server/Registrar Tier 2 ENUM Call Control Call Control Call Control Call Control
      • IN NAPTR 10 10 "u" "E2U+sip" “!^.*$!sip:tkershaw@verisign.com!”
      • IN NAPTR 10 10 "u" “E2U+mailto" “!^.*$!mailto:tkershaw@verisign.com
    Device Resources WhoIs? Perimeter Security and Interop Resources Option 1 Option 2 Option 3
  • 22. Models for MMS
    • Mobile operators have a different problem:
    • Since endpoints do not have IP addresses, they will be ported with LRNs
    • When a discovery takes place, they want a mapping of the phone number or LRN to a mailto: address
    • Mailto address will correspond to an MMSC in the destination network
    • Using this method eliminates the overhead of using the SS7 network and makes delivery more efficient
    • Requires an up-to-date mail to address database
    • This problem space is small (100 mobile operators x 3000 LRNs x 2 mailtos
    • Private no/low cost solutions already out there for this
  • 23. Conclusions
    • Biggest portability issue for VoIP carriers is geographic portability
    • This will become an increasingly focal issue
    • VoIP operators do not benefit from extending LNP infrastructure to URIs or IP addresses in the immediate term
    • Requiring a second dip to an external directory does not make sense – support E.164 portability directly on the IP network
    • Mobile operators do have a strong need for an LRN to mailto solution – and there are solutions out there
    • We must be very careful in our architectural decisions – the impacts are far reaching and in some cases we are solving problems before they manifest themselves
    • In VoIP, E.164 is a NameSpace, not an Address – need to treat it accordingly
  • 24. Thank You! [email_address] 703-948-4509