Building Blocks of NGN ENUM - Promises or Reality?

Transcription

1 Building Blocks of NGN ENUM - Promises or Reality? Regulations under Challenge 13th CEPT Conference Berlin, October 12th, 2006 Richard Stastny, ÖFEG* * The opinions expressed here may or may not be that of my company October 2006 Richard Stastny 1 Is ENUM Going a Full Circle? User ENUM User ENUM Infrastructure ENUM Infrastructure ENUM Private ENUM Private ENUM Private ENUM Private ENUM Private ENUM October 2006 Richard Stastny 2 1

2 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. ) The purpose of ENUM is to enable the convergence between the PSTN and the Internet October 2006 Richard Stastny 3 ENUM in a nutshell take an E.164 phone number turn it into a FQDN e164.arpa. query the DNS (for NAPTR) returns list of URIs sip:richard@iphone.at mailto:richard.stastny@oefeg.at sms tel: IN NAPTR "u" E2U+sip!^.*$!SIP:richard@iphone.at!. October 2006 Richard Stastny 4 2

3 The basic idea of ENUM (RFC3671) The basic idea of ENUM was to allow end-users to opt-in with their EXISTING phonenumbers 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 October 2006 Richard Stastny 5 ENUM Implementations Delegations in e164.arpa as of Oct 4th, Greece 31 Netherlands 33 France Trial closed 350 Gibraltar 353 Ireland Trial 354 Iceland 358 Finland 359 Bulgaria 36 Hungary 374 Armenia 386 Slovenia requested 39 Italy 40 Romania 41 Switzerland 420 Czech Republic Trial 421 Slovakia Trial 423 Liechtenstein Trial 43 Austria 44 UK Trial 46 Sweden Trial 47 Norway 48 Poland 49 Germany 246 Diego Garcia 247 Ascension 262 Reunion (fr) 290 Saint Helena 508 St. Pierre and Miquelon (fr) 55 Brazil 590 Guadeloupe (fr) 594 French Guiana 596 Martinique 61 Australia Trial 63 Philippines Trial 66 Thailand 65 Singapore Trial 81 Japan Trial 82 Korea Trial 84 Vietnam 86 China Trial Global s? VISIONng UPT 971 UAE 1 North America (US, CA, Jamaika) additional Asian countries (Taiwan ) have trials, but not in.arpa October 2006 Richard Stastny 6 3

4 The draw-backs of the original approach Privacy concerns reduced the usability of ENUM basically to VoIP Most VoIP providers do not provide end-users with SIP URIs to be reached on the Internet without termination fees Why should an end-user pay for the benefit of other users? How to overcome Metcalfe s Law? Nobody understands ENUM October 2006 Richard Stastny 7 But the real problem is: 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 October 2006 Richard Stastny 8 4

5 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 October 2006 Richard Stastny 9 Infrastructure ENUM first try A tree for service providers is needed ETSI created TR ENUM Scenarios for User and Infrastructure ENUM discussing the options and the problems: It should be a single global tree Service provider opt-in No regulatory involvement required But: Who is in charge? Where to place the tree (public, private) How to get ALL service providers to agree on this etc., etc. October 2006 Richard Stastny 10 5

6 Nevertheless, a solution was needed IP-basedserviceproviderswantedto peer (interconnect) their SIP traffic based on E.164 numbers So a number of VoIP peering federations including some kind of E.164 resolution where established: XConnect, VPF, e164.info, SPIDER, Most of them based on ENUM technology October 2006 Richard Stastny 11 The ENUM Matrjoschkas October 2006 Richard Stastny 12 6

7 Private ENUMs Also called: Operator ENUM Enterprise ENUM Carrier ENUM This is currently how service providers interconnect: 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? October 2006 Richard Stastny 13 Routing on the PSTN Originally done by digit analysis and number translation tables based on dialed digits Purpose: Routing and charging Digit analysis based on number blocks assigned to countries, switches and providers Routing: finding the next hop Done in every network element (switch) individually Huge administrative overhead, individual tables per switch required Number portability requires in addition the implementation of IN services October 2006 Richard Stastny 14 7

8 Number Portability - Terminology Originating network/exchange Donor network/exchange Serving network/exchange Transit network/exchange Recipient network/exchange Routing number October 2006 Richard Stastny 15 Number Portabiliy - Generic incoming call Transit (optional) 1st step of the routing process, based on dialled digits Serving 2nd step of the routing process, based on routing number Recipient Serving Exchange Recipient Exchange customer with ported number T NOTE The serving network may be the originating network and/or the donor or a transit network. October 2006 Richard Stastny 16 8

9 NP Onward Routing Originating IAM Transit (s) (A) IAM Donor DB a1) IAM b) IAM Called Subscriber Calling Subscriber Transit (s) (B) a2) IAM Recipient T Onward routing by donor network (DB) October 2006 Richard Stastny 17 NP Drop Back Originating IAM Transit (s) (A) a1) IAM IAM Dropb. b) IAM Donor DB Called Subscriber Calling Subscriber Transit (s) (B) a2) IAM Recipient T Lasting relation Temporary relation Drop back by donor network (DB) with rerouting information and onward routing by a transit (or the originating) network October 2006 Richard Stastny 18 9

10 NP Query on Release Originating IAM Transit (A) a1) IAM DB IAM REL b) IAM a2) IAM Donor Called Subscriber Calling Subscriber Transit (s) (B) Recipient T Lasting relation Temporary relation Query on Release by transit (or originating) network (DB) October 2006 Richard Stastny 19 NP All Call Query Originating a1) IAM Transit Donor DB b) IAM a2) IAM Called Subscriber Calling Subscriber Recipient T Lasting relation Temporary relation All Call Query by originating network -> Infrastructure ENUM October 2006 Richard Stastny 20 10

11 Implemented solutions All of these solutions are currently implemented, depending on country and numbering range DB may be de-centralized or centralized But all implementations are country specific and also work only countrywide Infrastructure ENUM is equivalent to a global ACQ solution October 2006 Richard Stastny 21 Further reading ITU-T Rec. E.164 Supplement 2 Number Portability RFC Number Portability in the Global Switched Telephone (GSTN): An Overview October 2006 Richard Stastny 22 11

12 Infrastructure ENUM second try All types of private ENUMs have serious disadvantages: limited reach, no global solution, how to peer with other federations? Only numbers from providers participating in the given federation can be reached To enable global reachability on IP, a single, common and global tree is required. The first goal of Infrastructure ENUM is to create an anchor place where any E.164 number can be found and will: either be mapped directly to an ingress point of the destination network, or at least hints can be found in which private E.164 resolution spaces the number can be resolved. October 2006 Richard Stastny 23 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 October 2006 Richard Stastny 24 12

13 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 WG established 8. February 2006 October 2006 Richard Stastny 25 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. October 2006 Richard Stastny 26 13

14 Scope ENUM and SPEERMINT Number ENUM Lookup Infrastructure ENUM I-ENUM SIP URI Policy Lookup Policy Database SPEERMINT Routing Parameter October 2006 Richard Stastny 27 Current I-Ds in ENUM Infrastructure ENUM Requirements The E.164 to Uniform Resource Identifiers (URI) Dynamic Delegation Discovery System (DDDS) Application for Infrastructure ENUM Combined User and Carrier ENUM in the e164.arpa tree (interim solution) The ENUM Branch Location Record (interim solution) IANA Registration for an Enumservice to Hint to E.164 Resolution Namespaces (ERN) October 2006 Richard Stastny 28 14

15 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) October 2006 Richard Stastny 29 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 October 2006 Richard Stastny 30 15

16 What about User ENUM? User ENUM may finally co-exist with Infrastructure ENUM Infrastructure ENUM will basically be used as a SS7 replacement for SIP- based services User ENUM is an end-to-end Internet service usable for any kind of end user communication End user will never host all their services with one provider It may be used as an overlay for any type of services communities and enterprises. October 2006 Richard Stastny 31 Thank you Richard Stastny ÖFEG richard.stastny@oefeg.at October 2006 Richard Stastny 32 16