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Internet Telephony; -existing and emerging standards. Lill Kristiansen, Ericsson AS Product Unit Internet Lill.Kristiansen@eto.ericsson.se www.ericsson.com/ipservices www.ericsson.com/gatekeeper. Enablers for telephony over IP. WEB explosion user friendly GUIs, IP as common denominator
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Internet Telephony;-existing and emerging standards Lill Kristiansen, Ericsson AS Product Unit Internet Lill.Kristiansen@eto.ericsson.se www.ericsson.com/ipservices www.ericsson.com/gatekeeper Lill Kristiansen, Ericsson AS
Enablers for telephony over IP • WEB explosion • user friendly GUIs, • IP as common denominator • A global data network with relatively cheap bandwidth • Powerful Multimedia PCs • A need for advanced services • ex: ‘true CTI’ integration of company’s web pages, customer base, attendants, click-to-dial, email etc Lill Kristiansen, Ericsson AS
The Market Public multi-mediafor wirelessnerds? Public multi-media, broadband Enter-prisemulti-media Long distance telephony Soft PBX The market for real-time services over IP will evolve from the current ‘toll bypass’ market. In the long run it is about services and innovations!(over a cheap infrastructure) Lill Kristiansen, Ericsson AS
‘Problems’ • High bandwidth, real-time media over IP • need for ‘managed network’, QoS, accounting,... • Locating other users • machine addresses and / or user-id’s • users on PSTN (22 xx yy zz) • Authenticating users • Knowing other user's communication capabilities (full blown MM-PC or simple audio device?) Lill Kristiansen, Ericsson AS
Factors driving IP telephony • Innovation • Deregulation • Convergence • StandardsAll issues are important! Focus in this talk is on the standard issues Lill Kristiansen, Ericsson AS
Ericsson policy on IP-telephony standards • Standards are important! • Ericsson active in H.323, Tiphon, IETF etc • Ericsson active in inter-ops (IMTC, Tiphon others) • Standardise what is needed! (only) • Standards are needed for inter vendor and inter domain issues, including ‘roaming users’ • Allow for innovative, competitive services and applications ‘on-top of’ or ‘along side’ the standards Lill Kristiansen, Ericsson AS
IP Telephony implementations /IP Telephony standards • CU-SeeMe • ITU-T: H.323 suite • IMTC: Interoperability efforts • ETSI: TIPHON • Public case, interworking with legacy. ,mobility • IETF wg: MMUSIC (SIP), IPtel,... Lill Kristiansen, Ericsson AS
Outline of the rest of the talk: • Basics about H.323 • GK, GW, endpoints, MCU • call and media/connection separation • About ETSI Tiphon project • based on H.323 (with public voice focus) • PC-phone, phone-PC, PC-PC + mobility • SIP (IETF) • Other standards (brief) Lill Kristiansen, Ericsson AS
ITU-T H.323 is ... • An ITU-T standard • For multimedia communication: • Audio (mandatory) • Video (optional) • Data (optional) • On packet-based networks… • v.1 main target LAN environments (1 ‘zone’ only) • v.1. datacom initiative (now more mixed data+telecom) • H.323 is an evolving standard (v3 is coming soon) Lill Kristiansen, Ericsson AS
The H.323 umbrella H.323 Network control H.225.0 Session control H.245 Media coding Gateways H.246 Security H.235 RAS control Suppl. S H.450 Video coding Audio coding Data Call control H.26X G.7XX T.120 (H.450 classicalstandardised PBX-like supplementaryservices are optional) Real-time transportRTP Lill Kristiansen, Ericsson AS
H.323 Entities Lill Kristiansen, Ericsson AS
H.323 Network (1 zone, 1 GK shown) Lill Kristiansen, Ericsson AS
User Awareness - Authentication - Security • Make sure the END USER is who he claims to be... Lill Kristiansen, Ericsson AS
H.323 Gatekeepers • Call by alias, instead of machine addresses • “Espen” vs “193.161.191.216” • user/subscription oriented • Administrate use of network bandwidth • Managing network resources (gateways, MCUs...) • In v1: 1 GK 1 zone (user & bandwidth) • Improvements coming: N zones, roaming etc. Lill Kristiansen, Ericsson AS
H.323: an evolving standard • v1: mostly LAN oriented many roundtrips, many TCP conn. • v2: Adding ‘fast start’ and security • products ‘hot from vendors’ spring ‘99 • v3 (ready May ‘99) • Inter-op test events are still important! • ‘foilware’ standard claims are not enough Lill Kristiansen, Ericsson AS
Direct call alternative: Caller gets contact address of called party from GK ARQ to GK for bandwidth admission Lill Kristiansen, Ericsson AS
Gatekeeper routed call alternativeGK handles (user) registration and call setup (opt. Including user/call related value added services) Registatipn phase ARQ may be ‘pregranted’ I.e. GK may allow for incoming calls during registration phase (decreases the call setup time) Call setuphase Lill Kristiansen, Ericsson AS
Signaling: 2 gatekeepers routing, unknown B party Lill Kristiansen, Ericsson AS
ETSI Tiphon projecthttp://www.etsi.fr/TIPHON/TIPHON.htm • focus on interworking with PSTN/PISN • GW component specifications • scalability (public case) • inter-domain issues • mobility and wireless aspects (just started) • incl.: user mobility, service mobility, terminal mob. • wireless specifics (reuse of radio specs.) • based (mostly) on H.323 on the IP side Lill Kristiansen, Ericsson AS
Phase 1 Phase 3 Scenario 1(PC - Phone) PSTN abonnent IP baserad abonnent Scenario 2(Phone - PC) IP baserad abonnent PSTN abonnent Scenario 3(Phone - Phone) PSTN abonnent IP PSTN abonnent Scenario 4(PC - PC via PSTN) Scenario 0(PC - PC) IP baserad abonnent IP baserad abonnent IP baserad abonnent IP baserad abonnent PSTN IP Mobility added Scenarios- phases Phase2 WE ARE HERE SPRING 99 Lill Kristiansen, Ericsson AS
Goals • Work quick: Meetings every 2nd month, using e-mails in between • Work smart: Do not reinvent the wheel: Use existing standards where existing (IETF eller ITU-T protocols whereever possible) • Work global: Not a European standard (every 3rd meeting in America, next in Bankok in May) • Based on H.323 series and existing SCN/PSTN standards • Application based solutions that can be used by different types of operators Lill Kristiansen, Ericsson AS
Tiphon workgroups • Wg1 Requirements • Wg2 Architecture • Wg3 Protocols • Wg4 Addressing, naming • Wg5 Speech Quality and QoS • Wg6 Testing • Wg7 Mobility and wireless aspects (new) Lill Kristiansen, Ericsson AS
DTS 03003, Annex G/H.323 DTS 03005 Specifikations and reports phase 2 Requirement DTR 01002 Architecture: TS 101313 (finished) GK - GK: DTS 03003 Basic call: DTS 03005 Security: DTS 03006 Addressing: DTS 04002 Quality: DTR 05001 Testspec.: DTR 06004 Tiphon Phase 2 architecture DTS 03004 G GK GK D BacK End/clearing house A C F H.323 (MM) clientPC or H.323 telephone E.b J Media GW Signalling Controller GW PSTN N The protocols internal to the PSTn GW are not finished B Media GW E.a Decomposed GW to PSTN Lill Kristiansen, Ericsson AS
PSTN (or Private SCN) GW (FFS) Wireless GW ’Number’ translation needed +999 1234 5678 PublicTiphon Systems(multiple domains) EnterpriseTiphon System PublicTIPHON System Gatekeepers Lill.K-sen@eto.ericsson.se IP access (best effort) IP Net Lill.K-sen@hotmail.com Lill Kristiansen, Ericsson AS
Solutions(?) To be studied by Tiphon: • New ’global country code’ ( e.g. 999) proposed in Tiphon (awaiting ITU decision) • may indicate IP-technology • or global MM roaming service • similar to Nextel 850 ’Interfon’ service inside Norway • ’user@domain’ like user names • indicating home-GK (HLR/Home-agent/SIP like solution) • IP addresses (or ’temporary routing numbers’) for media routing Lill Kristiansen, Ericsson AS
Quality classes for TIPHON System 4 (Best) 3 (Hight) 2 (Medium) 1 (Best effort) TIPHON speech quality Eqivalent or Eqivalent or Eqivalent or better than better than better than G.711 G.726 GSM-FR One way delay <150 ms <250 ms <450 ms Call Direct IP setup addressing <1.5 s <4 s < 7 s times (SCN) E.164 translation to <2 s <5 s <10 s IP-address (SCN) E.164 to <3 s <8 s <15 s IP-address via clearinghouse or roaming Email alias translated <4 s <13 s <25 s to IP-address Lill Kristiansen, Ericsson AS
SIP (Session Initiation Protocol) IETF RFC-2543 for ‘invitations’ (call setup) to multimedia sessions • Lightweight Text based, HTTP-like • Request / Response • extensible • Using UDP (and resending if needed) • Invite to SIP://user@domain + SDP for media • Does not address bandwidth/QoS • Does not address interworking with PSTN Lill Kristiansen, Ericsson AS
H.323 Heavy (ANS.1 based) Operator can control the network (and bandwidth use) GK may use a service node on top Off the shelf products for PC-PC cases and GW with legacy SIP Simple implementation Network resources out of scope May control incoming calls (invite + opt. CPL) Some prototypes Just passed as RFC-2543 H.323 vs SIPAnalyse your needs and business case(s) Lill Kristiansen, Ericsson AS
Other standards/consortium initiatives • IPtel (WG in IETF) • click-to-dial etc. (‘from web-to-POTS’) • does not address ‘media-over-IP’ (yet?) • CPL Call Processing Language (IETF) • ongoing: standardising a language for call control • Parlay for a Call-Control API (www.parlay.org) • a demo held, no products (yet?) • TINA-C (www.tinac.com) • lots of specification during 5 years, no products (yet?? ) • others? + all the proprietary stuff Lill Kristiansen, Ericsson AS
Service Control Service Control Gatekeeper Call Control Call Control Media Control Media Control What about the new services? • H.450: Mixing service- and call control Terminal Lill Kristiansen, Ericsson AS
From Tipia (www.tipia.org) (service operator consortium) Global credit card service CUG (closed user group) between operators VPN (Virtual Private Network) between operators Virtual Home Environment Universal roaming Global directory service Voice controlled mail box Classical supplementary services (H.450 based) Call forward busy Call forward unconditional Call waiting Call transfer More to come ...(PBX based) Example of services (requirement input to Tiphon) Other services? Need for standards? What can (not) be solved by VHE? Lill Kristiansen, Ericsson AS
Services Services User data User data Network: Network: Terminal: Dissected gatekeeper and mobility (VHE) Visiting domain Home domain Roaming user Lill Kristiansen, Ericsson AS
Services and mobility Services User/subscriber database Home GK All incoming calls goes via home_GK (‘similar’ to GSM-HLR/SCP) Also oiutgoing calls goes via home GK. VHE (Virtual Home Environment) concept, (input to Tiphon) • The user may log on from everywhere. • Visited GK controls his own resources • The visited GK contacts home GK’n and routes the call (but not necessarily the media) via home GK. • The user have accesses to the same services as when being ‘at home’ • No time consuming process of standardising services is needed • Allowing competitive service provisioning, innovation. • No need to standardise and transfer service profiles Registration via visiting GK to home GK Visited GK Lill Kristiansen, Ericsson AS