Slide 1 Nicklas Beijar - TRIP, ENUM and Number Portability TRIP, ENUM and Number Portability Nicklas Beijar

Slide 2 Nicklas Beijar - TRIP, ENUM and Number Portability Contents 1. Current situation, problem description 2. TRIP 3. ENUM 4. Scenarios 5. Number portability 6. Conclusions TRIP, ENUM and Number Portability

Slide 3 Nicklas Beijar - TRIP, ENUM and Number Portability Current situation Terminal location End terminal located with signaling protocol and DNS Mapping from name (E.164, URL, ) to address (IP address) Mapping stored in location server (gatekeeper, signaling server) Manually configured or obtained through registration Directory servers (ULS, ILS) E.164 numbers selected for IP Telephony by TIPHON Can be entered with numeric keypad Users don’t need to know if the receiver is a IP or PSTN subscriber

Slide 4 Nicklas Beijar - TRIP, ENUM and Number Portability Current situation Gateway location Similar to terminal location, Gateway selected manually by caller or by signaling server New selection if gateway is unavailable Number portability Change service provider, location or service type without changing telephone number IP Telephony -> number portability between PSTN and IP Currently available in the PSTN only Mapping from directory number to routing number (or routing prefix) Routing number has hierarchy Mapping performed by Intelligent Network (IN)

Slide 5 Nicklas Beijar - TRIP, ENUM and Number Portability Given a phone number corresponding to a specific host on the IP network, determine the IP address of the host.  Terminal location problem Given a phone number corresponding to a terminal on the PSTN, determine the IP address of a gateway capable of completing calls to that phone.  Gateway location problem ProblemsProblems

Slide 6 Nicklas Beijar - TRIP, ENUM and Number Portability ProblemsProblems Mappings are not distributed between signaling servers and location servers E.164 numbers cannot be used globally Users must select gateway manually Which gateways are available and suitable for this call?

Slide 7 Nicklas Beijar - TRIP, ENUM and Number Portability TRIPTRIP Telephony Routing over IP IETF protocol, still at draft stage Distributes routing information between location servers Information about gateways and the numbers reachable through them Routes to gateways and signaling servers Modeled after BGP-4 Gateway selection driven by policies Interdomain protocol between Internet Telephony Administrative Domains (ITAD) Interdomain synchronization based on SCSP and OSPF Information transported as attributes of the UPDATE message Expandable

Slide 8 Nicklas Beijar - TRIP, ENUM and Number Portability NameDescription Withdrawn routesList of telephone numbers that are no longer available. Reachable routesList of reachable telephone numbers. Next hop serverThe next signaling server on the path towards the destination. Advertisement pathThe path that the route advertisement has traveled. Routed pathThe path that the signaling messages will travel. Atomic aggregateIndicates that the signaling may traverse ITADs not listed in the routed path attribute. Local preferenceThe intra-domain preference of the location server. Multi exit discThe inter-domain preference of the route if several links are used. CommunitiesFor grouping destinations in groups with similar properties. ITAD topologyFor advertising the ITAD topology to other servers in the same ITAD. AuthenticationAuthentication of selected attributes. TRIP attributes

Slide 9 Nicklas Beijar - TRIP, ENUM and Number Portability Structure of a TRIP node

Slide 10 Nicklas Beijar - TRIP, ENUM and Number Portability ENUMENUM tElephone NUmbering Mapping RFC 2916 Maps E.164 numbers into Uniform Resource Identifiers (URI) The URIs represent different ways to contact a host SIP, H.323, TEL, ,... Uses the Domain Name System (DNS) E.164 number rewritten as a domain name: > e164.arpa

Slide 11 Nicklas Beijar - TRIP, ENUM and Number Portability $ORIGIN e164.arpa. IN NAPTR “u” “sip+E2U” IN NAPTR “u” “mailto+E2U” IN NAPTR “u” “tel+E2U” “!^.*$!tel: !”. Example NAPTR records

Slide 12 Nicklas Beijar - TRIP, ENUM and Number Portability Sample top level delegations from ITU: 3.3.e164.arpa IN NS ns.FR.phone.net. ;France e164.arpa IN NS ns.FI.phone.net. ;Finland Sample national delegations: e164.arpa. IN NS ns.ServiceProviderX.net. Sample service provider’s configuration: e164.arpa. DNAME ns.hut.fi. Sample service registrar configuration: * ns.hut.fi. IN NAPTR ”u” ”ldap+E2U”\ “$!ldap://ldap.hut.fi/cn=\1!”. Example reachme service

Slide 13 Nicklas Beijar - TRIP, ENUM and Number Portability Call from IP-based network to PSTN

Slide 14 Nicklas Beijar - TRIP, ENUM and Number Portability Call from PSTN to IP-based network

Slide 15 Nicklas Beijar - TRIP, ENUM and Number Portability Number portability Scenarios for hybrid PSTN-IP networks: 1.The number moves within the PSTN. 2.The number moves between PSTN and IP. 3.The number moves within the IP network. ENUM allows the mapping to be modified at different levels Another gateway may be more suitable  In most cases, information in ALL protocols must be updated

Slide 16 Nicklas Beijar - TRIP, ENUM and Number Portability ConclusionsConclusions TRIP solves the gateway location problem Distributes routing information between location servers ENUM solves the terminal location problem Provides mapping between names to addresses E.164 numbers In the PSTN, number portability implemented with IN Number portability can be implemented with TRIP and ENUM Still missing Automatic updating of infomation between TRIP, ENUM and IN Gateway location for the PSTN  CTRIP