1. Standards First!™

2. Fall Forum - Seattle, Washington - October 2001 H.450 Supplementary Services for H.323 Systems Karl Klaghofer Siemens AG Standards First!™

3. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Contents   Scope of H.450   Architecture   Example call flows   Gateway Interworking   Standardization aspects   Summary

4. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Scope (1) – What is H.450 about ? ITU-T umbrella standard for Telephony / Multimedia supplementary services for H.323 systems, for features that need signalling over the IP network beyond what is defined within H.323 base signalling protocol Examples: u u Three Party Services u u Call Redirection Services u u Team Function Services u u Unsuccessful Call Services u u Attendant related services u u …

5. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Scope (2) - H.450 as “Building blocks” for Applications Examples:   Call Center, Automatic Call Distribution (ACD)   Using Call Transfer service to redirect calls from the ACD server to an ACD agent   Use Call Intrusion/silent monitoring service for ACD supervisor services   Multimedia Messaging   Use of Call Diversion service to forward to Messaging Center   Use Message Waiting Indication service by Messaging Center to notify the served user   Integration with other Applications   Integrate with E-Mail   Integrate with world of organizers (e.g. calendar based call diversion)

6. Standards First!™ Fall Forum - Seattle, Washington - October 2001 H.450 Signalling FE IP / H.323 Architecture (1) - Principles   Functional, symmetrical Protocol derived from ISO “QSIG” protocol, optimized for IP/H.323 environment   Independent of type of network (Private or Carrier)   Media independent   Flexible in architecture:  Fully distributed model Intelligent endpoints supporting H.450; network transparent for H.450 -> the Internet/Intranet paradigm  Centralized model H.450 as the networking feature protocol -> the traditional telephony model EP Gatekeeper / Proxy EP Gatekeeper / Proxy Endpoint FE Functional Entity

7. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Architecture (2) – Example H.450 Endpoints & Entities IP / H.323 Network Soft client IP Phone Server Endpoints - Group Features - - Proxies H.450 Signalling Gatekeeper / Proxy Stimulus EP GWY/BS to Wireless GSM, W-LAN, Bluetooth,... Fax Gateway (to QSIG, ISDN,…)

8. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Architecture (3) – H.450 in H.323 Protocol Model G.7xx RTP RTCP H.225.0 H.245 Unreliable Transport (UDP) Reliable (TCP) Network Layer (IP) Applications H.26x H.225 RAS … H.450.3 H.450.2 H.450.1

9. Standards First!™ Fall Forum - Seattle, Washington - October 2001 H.225.0 (Q.931) IE's Allows for Manufacturer specific extensions using Object Identifier that indicate the manufacturer User-user IE (H323-UU-PDU) H450 Supplementary Service Component NFE I H.450 Feature 1 H.225.0 message (e.g. SETUP) TCP/IP packet h323-message -body Service APDUs e.g. Setup-UUIE: Fast Start, Endpoint type, Source Address, Dest Address,... Architecture (4) – H.450 Signaling within H.323 messages H.450 Feature 2 Ext Proprietary “H.450 like” feature 3 How to to react if not understood ? - -Ignore - -Reject - -Clear call Destination of the Feature ? - - endpoint - - any entity - - a specific one

10. Standards First!™ Fall Forum - Seattle, Washington - October 2001 EP A EP B Example Call Flows (1) – Single Step Transfer (H.450.2) EP C FACILITY ctInitiate (addressC,..) SETUP ctSetup (TransferNbA,..) CONNECT ctSetup.Res REL COM ctInitiate.Res Active Call Active call Idle

11. Standards First!™ Fall Forum - Seattle, Washington - October 2001 EP AEP B Example Call Flows (2) – Automatic Callback on Busy (H.450.9) Active Call SETUP (ccbs) RELEASE COMPLETE (ccbs.Result) Monitoring User B phase SETUP (ccExecPossible) A called B – B met busy B becomes available ALERT / CONNECT SETUP (ccRingout) RELEASE COMPLETE

12. Standards First!™ Fall Forum - Seattle, Washington - October 2001 A Example Call Flows (3) – Call Pickup Group w/Pickup Server (H.450.5) B C D Pickup Group Server FACILITY pickup groupNotification (pickup address B, callingUserA, pickupId,…) SETUP (pickRequ, pickupID) SETUP pickExe.inv CONNECT pickExe.Res Active Call SETUP ALERTING Alerting SETUP (groupNotification)

13. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Gateway Interworking (1) - Opportunities Opportunity for Gateway Interworking of H.323/H.450 Features with corresponding Features of other networks/systems for end-to- end feature operation in inhomogeneous networks:  PBX interworking:   QSIG,   DPNSS,   Proprietary PBX protocols  Public Network interworking:   DSS1   US ISDN Protocols (NIx)   SS7  Interworking with Non-H.323/H.450 VoIP systems:   SIP

14. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Gateway Interworking (2) – Example QSIG GWY H245 H.225.0 TCP UDP IP MAC ISDN QSIG H.323 / H.450 Voice G.7xx RTP IP MAC G.7xx UDP IP MAC G.711 B-Channel G.711 ISDN UDP RTP User Plane Control Plane QSIG Basic call QSIG Suppl Service QSIG GF Gatewayinterworking Gatewayinterworking D-channel QSIG Basic Call D-channel QSIG GF QSIG Suppl Service Voice H450.1 H450.X H245 H.225.0 TCP UDP IP MAC H450.1 H450.X H.450 based on QSIG concepts Corresponding functions in both worlds allows easy interworking Smooth migration from SCN to IP Features available End-to-end between LAN and PBX H.323/H.450 Gateway IP/LAN PBX

15. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Gateway Interworking (3) – What about SIP ?   Internet drafts available for H.323 – SIP Interworking for Basic Call; with first products available on the market   Desire for Interworking between H.323 and SIP also on Supplementary Services level – first candidates:   IETF Work item: SIP Call Transfer   Further SIP drafts available: MWI, Call Diversion, etc. Supplemen- tary Service IW Basic Call IW H.323/H.450 VoIP System SIP VoIP System H.450 SIP SS H.323 SIP BC H.323-SIP Gateway

16. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Standardization – Methods All Standards of the H.450 series of ITU-T Recommendations follows the same, consistent method of specification:   Stage 1 Service Description – Users Perspective   Stage 3 Service Description – Procedures, Interactions   Call Flow Diagrams   Generic API definition   Syntax definition (ASN.1)   SDLs  High degree of interoperability between different implementations can be expected

17. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Standardization – Status (1) Published ITU-T SG16 H.450.x standards – 12 Recommendations that cover more than 25 key features 12 Recommendations that cover more than 25 key features:  H.450.1 Generic Functions (Framework, base methods)   Call Related & Call independent H.450 signalling   Remote Operation Service - ROS (Invoke, Return Result, Return Error, Reject)   Action Indicator (i-apdu)   Adressed entity (NFE)   Manufacturer Specific Information Extension Mechanism (MSI)  H.450.2 Call Transfer for H.323   Single Step Transfer (w/o Consultation)   Transfer w/ Consultation   Transfer into Ringing/Active  H.450.3 Call Diversion for H.323   Call Forwarding Unconditional (CFU)   Call Forwarding on Busy (CFB)   Call Forwarding on No Reply (CFNR)   Call Deflection (CD)

18. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Standardization – Status (2)  H.450.4 Call Hold for H.323   Near End Hold   Remote End Hold  H.450.5 Call Park and Call Pickup in H.323   Directed Park / Directed Pickup   Group Park / Group Pickup   Call Pickup Groups  H.450.6 Call Waiting in H.323  H.450.7 Message Waiting Indication for H.323   MWI Activation, Deactivation   MWI Interrogation   Message Waiting Callback (MWCB)  H.450.8 Names Identification in H.323   Calling, Connected, Alerting, Busy Name Indication  H.450.9 Call Completion for H.323   Call Completion on Busy (CCBS)   Call Completion on No Reply (CCNR)

19. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Standardization – Status (3)  H.450.10 Call Offering for H.323  H.450.11 Call Intrusion for H.323   Intrusion / Break in at Busy User   Silent Monitoring   Recording  H.450.12 Common Information   Feature Capabilities   Feature Control (do not hold, do not transfer, call type...)   Party Category (user, attendant,...) H.450 is on the ITU-T SG16 work program also in its new study period (- 2004); i.e. further H.450.x Rec. will be added Other standardization bodies H.450 activities:   ECMA TC32   Published Interworking Standards for H.450.x – QSIG Interworking   ETSI Tiphon   Published H.450 Protocol Implementation Profiles (PICS)

20. Standards First!™ Fall Forum - Seattle, Washington - October 2001   Open, standard feature protocol for H.323 based IP systems   Multi-vendor interoperability   Flexible in Architecture   Enables smooth migration from SCN to IP   Customer can determine its own speed of migration   End-to-end feature availability between SCN and IP systems during migration phase via Gateway Interworking   Allows to distinguish from competitors   Standard Manufacturer Specific Escape mechanism for proprietary add- ons to standardized H.450 signalling   H.450 as application enabler Summary

21. Standards First!™ Fall Forum - Seattle, Washington - October 2001 Thank You ! Karl Klaghofer Siemens AG (karl.klaghofer@icn.siemens.de)