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VoIP and ENUM Short Introduction

VoIP and ENUM Short Introduction. AK-TK Workshop ÖFEG, March 11th , 2004 Richard STASTNY ÖFEG, Postbox 147, 1103-Vienna tel:+43 664 420 4100 mailto:richard.stastny@oefeg.at richard@stastny.com. Content. Some basic definitions The pieces Naming and addressing on the Internet, URIs

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VoIP and ENUM Short Introduction

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  1. VoIP and ENUMShort Introduction AK-TK Workshop ÖFEG, March 11th , 2004 Richard STASTNY ÖFEG, Postbox 147, 1103-Vienna tel:+43 664 420 4100mailto:richard.stastny@oefeg.atrichard@stastny.com

  2. Content • Some basic definitions • The pieces • Naming and addressing on the Internet, URIs • The Domain Name System (DNS) • VoIP and SIP • DDDS and ENUM • Putting all pieces together • ENUM History • Administration of ENUM Richard Stastny

  3. What is required to establish a communication? • (User) Identification (and authentication) • identification of the user to the service provider (registration) • userID/PW, IMSI, … • always provider specific, not portable • Address • current network access point of the user terminal device • e.g. IP address, … • network specific, not portable • Name • mapped (dynamically) to the current address of the terminal, where the user has registered himself • mostly service related, sometimes portable • Terminology not consistent: • e-mail address, address-of-record are names Richard Stastny

  4. What is a phone number? • always numeric (with some exceptions) • used as identifiers, addresses and names • started as addresses and identifiers • now with number portability and service numbers also used as names • Types of phone numbers • private, local, national, international • E.164 numbers or International Public Telephone Numbers • Structure of E.164 numbering plan • CC N(S)N e.g. CC NDC SN • max 15 digits including 1-3 digit CC • no prefixes or access codes -> part of dialing plans Richard Stastny

  5. Naming and addressing on the Internet • Addresses: IPv4 and IPv6 • Names: Uniform Resource Identifier (URIs) • alphanumeric character strings that identify abstract or physical resources on the Internet (RFC2396) • different formats, need to be defined in an RFC and registered with IANA • Examples: • http://www.enum.nic.at • http://80.121.237.198 • mailto:richard.stastny@oefeg.at • sip:richard@iphone.at • tel:+4317978032 • URI's may contain IP addresses or domain names • Domain names need to be resolved with the Domain Name System (DNS) Richard Stastny

  6. Domain Name System (DNS) • The DNS is a distributed lookup system arranged hierarchically • It consists of 4 components • the name space • the name servers making that name space available • the resolvers (clients) querying that name space • a protocol • Domains, zones and delegation • a domain is a set of host names consisting of a single domain and all the domain names below it • a zone is any domain name delegated by an ancestor zone, ie a point of delegation • it contains all descendant domain names not been delegated • delegation means that somebody else is responsible for the subdomain • Resource Record (RR) is a unit of data • it defines some attribute for the domain • eg. an IP address, a mail route, a VoIP signaling route, a delegation • What the DNS is doing: I have "x", give me "y" Richard Stastny

  7. Name Space und Name Server point of delegation „root“ Top Level Domains com at de se uk org net info biz int gov mil edu gTLDs ccTLDs Label Second Level Domains stastny microsoft co oefeg xxx.stastny.com oefeg atc yyy@stastny.com oefeg.co.at. Richard Stastny

  8. SIP “Trapezoid” Location Server DNS Server REGISTERjiri@195.37.78.173. DNS QUERY SRV iptel.org DNS details next slide SIP Inbound Proxy Server Outbound Proxy Server INVITEjiri@iptel.org SIP SIP jiri@iptel.org SIP caller@sip.com Media (RTP) User Agent A User Agent B Richard Stastny

  9. #1 #7 #6 #2 #3 #0 #4 #8 DNS SRV Query ? iptel.org Reply: IP Address of iptel.org SIP Server INVITEsip:jiri@195.37.78.173 From: sip:Caller@sip.com;tag=12 To: sip: jiri@iptel.org Call-ID: 345678@sip.com jiri@195.37.78.173 jiri INVITEsip:jiri@iptel.org From: sip:Caller@sip.com;tag=12 To: sip: jiri@iptel.org Call-ID: 345678@sip.com OK 200 From: sip:Caller@sip.com;tag=12 To: sip: jiri@iptel.org;tag=34 Call-ID: 345678@sip.com OK 200 From: sip:Caller@sip.com;tag=12 To: sip: jiri@iptel.org;tag=34 Call-ID: 345678@sip.com #5 ACK sip:jiri@195.37.78.173 Media streams Basic SIP Call-Flow (Proxy Mode) Location Database Proxy sip:jiri@195.37.78.173 Caller@sip.com Richard Stastny

  10. ENUM and DDDS • The Dynamic Delegation Discovery System (DDDS) is a generic system to implement a binding of strings to data stored in a database and is defined in RFCs 3401-3405 • The generic algorithm is defined in RFC3402 • RFC3403 defines the usage of DNS as database and therefore also defines the DNS Resource Record to be used: • Naming Authority Pointer or NAPTR • it also defines the fields of a NAPTR and how to process a NAPTR • ENUM is a DDDS application • RFC2916bis defines therefore • the algorithm: how to map a E.164 number to a domain name • the service_field = "E2U" 1*(servicespec) • how to register servicespecs with IANA (template) Richard Stastny

  11. ENUM in a nutshell • take phone number +43 1 979 33 21 • turn it into a FQDN 1.2.3.3.9.7.9.1.3.4.e164.arpa. • ask the DNS for NAPTR mailto:richard@stastny.com • returns list of URI’s sip:richard@iphone.at Richard Stastny

  12. How does ENUM work ? Telephone Number (TN): +43 1 979 33 21 translates to: 1.2.3.3.9.7.9.1.3.4.e164.arpa Tier 1 resolution to NS of authority ( pointer only) 1.2.3.3.9.7.9.1.3.4.e164.arpa. IN NS ns1.iphone.at Tier 2 resolution to NAPTR record and SIP URL controlled at the end office IN NAPTR 10 10 "u" “E2U+sip“ !^.*$!SIP:richard@iphone.at“! . set up call Richard Stastny

  13. fwd.pulver.com nic.at43.at So what is ENUM adding? ENUM DNS IN NAPTR 3.4.3.9.1.1.1.3.9.3.0.1.8.7.8.e164.arpa. ? ... NAPTR ... "!^.*!sip:19343@fwd.pulver.com!" DNS SRV lookup fwd.pulver.com SIP SIP server server +878103931119343 sip:19343@fwd.pulver.com session sip:axelm@nic.at43.at sip:mah@nic.at43.at sip:18341@fwd.pulver.com sip:19343@fwd.pulver.com Richard Stastny

  14. Bridging Internet & PSTN with ENUM Internetz PSTN sip:mah@nic.at +43 59966 366001 Media Gateway +43 664 4213465 ENUM DNS +31 20 535 4412 sip:axelm@nic.at +43 59966 366003 Richard Stastny

  15. +43780 179780 32 32@iphone.at +43179780 32 32@iphone.at ENUM Internet * GK oder SIP Server PBX GW GK GW TDM TDM TDM Options for Corporate Users 32@iphone.at 32 +43780 179780 32 +43179780 +43179780 32 Richard Stastny

  16. So how can ENUM be used? • Business: with IP PBX or IP Centrex • with geographic and/or numbers for networks (opt-in) • linking IP islands together globally via the Internet • Residential: with my geographic number (opt-in) • either as secondary line or as primary line (ported out) • Residential: with my mobile number • terminate IP originated calls on IP, plus evenually forwarding or forking to my mobile • operators may provide forced ENUM access from the PSTN • Residential and Business: ENUM-only number • IP device can be reached from PSTN and IP • calls may be dumped to IP in the originating network Richard Stastny

  17. ENUM and VoIP as a Trigger • ENUM is tightly linked with numbering and therefore with the regulatory framework • Deployment of ENUM is also tightly linked with the deployment of VoIP • Deployment of VoIP causes a direct conflict between Telco's and ISP's • Deployment of ENUM involves NRA's and Registries (in Europe primarily the ccTLD's) • ENUM and VoIP therefore cause a lot of questions and issues to surface. Richard Stastny

  18. A (very short) ENUM History • Sept. 2000 – IETF ENUM WG – RFC2916 • 2001 – Various Workshops (ITU-T, Europe, US, …) • 2002 – ITU-T Interim Procedures (IAB, RIPE-NCC) – ETSI SPAN11 TS "ENUM Administration in Europe" – Austrian ENUM Trial in operation (Sept. 2002) • 2003 – ETSI SPAN11 TS "Minimum Requirements for Interoperability of European ENUM Trials" – IETF RFC2916bis WGLC – Various national and international ENUM Trials – using different scenarios and numbering resources – and using different ENUM-enabled products • 2004 – ETSI ENUM Plugtests and Workshop – ENUM ready for production Richard Stastny

  19. arpa in-addr e164 3.4 0.8.7.9.7.1 Name Space + .arpa root com org net info int gov mil edu at de se uk gTLDs ccTLDs Tier 0 co oefeg stastny microsoft Tier 1 xxx.stastny.com oefeg atc yyy@stastny.com oefeg.co.at Tier 2 0.8.7.9.7.1.3.4.e164.arpa Richard Stastny

  20. The ENUM "Tiers" Registry Tier-0 International-RIPE-NCC and ITU-TSB National CC 43 CC 1 Directs the DNS query to the customer’s Tier-2 providers. An NS* record is provided for each subscriber’s telephone number Registry Registry Tier-1 Tier-1 Stores a list of service specific internet addresses in the form of URI’s in a DNS resource record called NAPTR for each subscriber. Returns the full list of Internet addresses associated with the E.164 number being queried. Provider Tier-2 *An NS record is an authoritative Name Server DNS record used to delegate to subordinates Richard Stastny

  21. ENUM Delegations Delegations in e164.arpa as of 11. March 2003 • 31 Netherlands • 33 France • 358 Finland • 36 Hungary • 374 Armenia • 40 Romania • 41 Switzerland • 420 Czech Republic • 421 Slovakia • 423 Liechtenstein • 43 Austria • 44 UK • 46 Sweden • 48 Poland • 49 Germany • 55 Brazil • 86 China • 246 Diego Garcia • 247 Ascension • 290 Saint Helena • 971 UAE • 88234 Antarctica Mobile • 87810 VISIONng UPT additional Asian countries (Korea, Japan, …) soon to come http://www.ripe.net/enum/request-archives/ Richard Stastny

  22. The End Thank you for your attention Contact (not Content) is KingDouglas Rushkoff Richard Stastny

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