Richard Stastny, ÖFEG*

1. Developments aroundInfrastucture ENUMand their relevance on NGNsWorkshop on NGN Interconnection and NumberingTRIS – TISPAN WG4Copenhagen, 18. January 2006 Richard Stastny, ÖFEG* * The opinions expressed here may or may not be that of my company Richard Stastny

2. Content • NGN/IP Interconnect – VoIP Peering • Some definitions • What is ENUM? • What kind of ENUM? • Infrastructure ENUM • Recent IETF developments • ENUM WG • SPEERMINT WG • Benefits in a nutshell Richard Stastny

3. Definitions • What are NGNs? • IP-based “networks” • “Service provider” “networks” offering real-time or near realtime IP communications • “Enterprise networks” • etc. •  Administrative Domains • What is Interconnection between NGNs? • a user registered in one administrative domain is able to contact (establish a session to) an user registered in a different administrative domain by using a Public User Identity (Address-of-Record, E.164 Number) • preferably via IP Richard Stastny

4. NGN/IP Interconnect (VoIP Peering) • If we take the All-IP paradigm seriously, we have two basic requirements: • Any real-time communication originating on IP and terminating on IP MUST stay on IP end-to-end • This implies, it MUST NOT use the PSTN/ISDN to interconnect. • Benefits are: • improved end-to-end functionality (BB codecs, IM, video, conferencing, presence, …) • Improved end-to-end QoS • No additional cost beside of IP-access • convergence possible at the end-user’s device Richard Stastny

5. Example IMS (TS 23.228) • Public User Identities • something one may put on a business card  a SIP URI or a TEL URI (in E.164 format) • Routing* within IMS shall use SIP URIs • (converted via DNS to IP addresses – RFC3263) • TEL URIs will require conversion to SIP URIs (via ENUM) Interconnection between IMS must be possible by using SIP URIs only * Routing = finding the next hop Richard Stastny

6. Possible Public User Identities • E.164 numbers • SIP URIs defined by provider: • sip:4319793321@telekom.at • sip:richard.stastny@aon.at • SIP URIs with self-provided domains: • sip:8431@kapsch.net • sip:richard.stastny@oefeg.at Richard Stastny

7. ENUM is defined by the IETF • Electronic or E.164 NUMber mapping is defined by the Internet Engineering Task Force (IETF) in RFC3761 as: • the mapping of „Telephone Numbers“ to Uniform Resource Identifiers (URIs) using the Domain Name System (DNS) in the domain e164.arpa • URIs are used to identify resources on the Internet (e.g. http://enum.nic.at ) • The purpose of ENUM is to enable the convergence between the PSTN and the Internet Richard Stastny

8. ENUM in a nutshell +43 720 203 211 • take an E.164 phone number • turn it into a FQDN 1.1.2.3.0.2.0.2.7.3.4.e164.arpa. • query the DNS (for NAPTR) • returns list of URIs sip:richard.stastny@iphone.at mailto:richard.stastny@oefeg.at sms tel:+436644204100 IN NAPTR 100 100 "u" “E2U+sip“ !^.*$!SIP:richard@iphone.at! . Richard Stastny

9. The basic idea of ENUM (RFC3671) • The basic idea of ENUM was • to allow end-users • to opt-in with their EXISTING phone-numbers on the PSTN • into e164.arpa • to provide OTHER end-users with the capability • to look up contact URIs on the Internet the above end-user wants to link to this number • This kind of ENUM is called User ENUM Richard Stastny

10. providerB.net providerA.net SIP Session establishment If this does not work, forget ENUM IP –based network DNS DNS SRV lookup providerB.net SIP SIP server server sip:bob@providerB.net sip:bob@providerB.net session sip:alice@providerA.net sip:eve@providerA.net sip:eve@providerB.net sip:bob@providerB.net Richard Stastny

11. IMS Richard Stastny

12. ENUM DNS providerB.net providerA.net E.164 Session establishment What is ENUM adding? IN NAPTR 0.1.4.0.2.4.0.8.7.3.4.e164.arpa. ? ... NAPTR ... "!^.*$!sip:bob@providerB.net!" DNS DNS SRV lookup providerB.net SIP SIP server server tel:+43780420410 sip:bob@providerB.net session sip:alice@providerA.net sip:eve@providerA.net sip:eve@providerB.net sip:bob@providerB.net Richard Stastny

13. What are the Benefits of ENUM? • ENUM is using the DNS • it’s there, it works, it’s global, it scales, it’s reliable, it’s open, anyone can use it… • saving CAPEX • Enables the originating administrative domain to do an All Call Query (ACQ) to find the destination network • Ultimate solution in Number Portability • Provisioning is done only by the destination (recipient) administrative domain for the E.164 numbers this domain is hosting • Saving OPEX • Enables all multimedia (MM) services for E.164 numbers for all sessions on IP end-to-end • Enables convergence (whatever that means) Richard Stastny

14. So what ENUM should be used? The ENUM Babuschka‘s Richard Stastny

15. The “ENUMs” • User ENUM • Private ENUM • Operator ENUM • Enterprise ENUM • Federation ENUM • Carrier ENUM • Infrastructure ENUM • EMINEM Richard Stastny

16. User ENUM • User ENUM requires • country opt-in • end-user opt-in • “Service providers” have no say in User ENUM • So Service Providers using IP-based technology need other solutions to be able to Interconnect • via IP-based technology and • using E.164 Numbers Richard Stastny

17. Private ENUM • Also called: • Operator ENUM • Enterprise ENUM • An administrative domain is setting up their own private ENUM DNS • May be used in addition to other solutions to route within own network • But does not solve the Interconnect problem with other administrative domains AND • requires extensive provisioning Richard Stastny

18. Federation ENUM • This is currently how “service providers” interconnect on IP: • Variants: • Private ENUM in a “walled garden” extranet (GSMA) • SIP Exchange with restricted access on the Internet (Cable providers, XConnect, SIP-IX, …) • public tree not in „e164.arpa“ (e164.info) • Advantages: • No user opt-in, NO REGULATORS INVOLVED, intrinsic peering agreements, savings in CAPEX, OPEX, MM-services • Disadvantages: • limited reach, • no global solution, • how to peer with other federations? Richard Stastny

19. Public Infrastructure ENUM • If Infrastructure ENUM is intended to allow the mapping of any E.164 number • that can be reached via IP • even if it terminates on the PSTN • to a SIP URI, • Infrastructure ENUM must be in the public DNS. • But this is useless, if the resulting SIP URI cannot be reached • So for Infrastructure ENUM also a global IP Interconnect (VoIP Peering) regime is required. • ENUM is an applet to VoIP Peering Richard Stastny

20. Standardisation in IETF • Two recent major developments in IETF regarding (VoIP) Interconnect: • ENUM WG extended scope to include Infrastructure ENUM • Voipeer BoFs to create new SPEERMINT WG • Session PEERing for Multimedia INTerconnect Richard Stastny

21. Separation of Scope • The ENUM WG is primarily concerned with the acquisition of Call Routing Data (CRD) e.g. a SIP URI, • while the SPEERMINT WG is focused on the use of such CRD. • Importantly, the CRD can be derived from ENUM (i.e., an E.164 DNS entry), or via any other mechanism available to the user. Richard Stastny

22. Number SIP URI Routing Parameter Scope ENUM and SPEERMINT Infrastructure ENUM ENUM Lookup I-ENUM Policy Database Policy Lookup SPEERMINT Richard Stastny

23. Current I-Ds in ENUM WG • Carrier/Infrastrucure ENUM Requirements • draft-lind-infrastructure-enum-reqs-01 • Combined User and Carrier ENUM in the e164.arpa tree • draft-haberler-carrier-enum-01 • IANA Registration for an Enumservice Containing PSTN Signaling Information • draft-ietf-enum-pstn-02 Richard Stastny

24. Current I-Ds in SPEERMINT • Terminology for Describing VoIP Peering and Interconnect • draft-meyer-voipeer-terminology-01 • Publishing SIP Peering Policy • draft-lendl-sip-peering-policy-00 • This documents proposes the use of DNS entries to publish a SIP proxy's policy for accepting incoming calls. Such published policies can be used to selectively establish peering relationships between VoIP service providers. Richard Stastny

25. Benefits in a nutshell • The major benefits of Infrastructure ENUM and SPEERMINT for (VoIP) carriers and (VoIP) service providers is to save costs: • Minimal CAPEX for setting up the required infrastructure to provide the routing data • Minimal OPEX for maintaining routing data: • Announce the E.164 numbers you host (in ENUM) • Announce the domains you host (in DNS) • (make bilateral or multilateral peering agreements) • Query ENUM and DNS to find any other destination provider Richard Stastny

26. The End Thank you Richard Stastny ÖFEG +43 664 420 4100 richard.stastny@oefeg.at http://voipandenum.blogspot.com Richard Stastny