1. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 1 MEDDAHI Ahmed (Ecole Nouvelle d Ingénieurs en Communication) E.N.I.C Cité Scientifique, rue G. Marconi 59658 Villeneuve d ’Ascq (France) Tel: +33(0)3-20.33.55.62 Fax: +33(0)3-20.33.55.98 email: meddahi@enic.fr * this paper was supported by the European Commission through the VirTEPPE project « Mobility issues in the context of distance learning services »*

2. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 2 CONTENT Introduction A distance learning tool based on ISDN A distance learning tool based on Internet Mobility issues SIP for providing distance learning services Conclusion

3. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 3 Ecole Nouvelle d’Ingénieurs en Communication New Communications Engineering Institute www.enic.fr Introduction

4. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 4 Introduction: Channels / Activities Training for Engineer Degree Initial training 5 years 335 for 2000 “Adult” training 18 months mini 200 for 2000 distant training (for Adult only) 3 years 100 for 2000 On-site TrainingOn-site Training Research / DevelopmentResearch / Development Pedagogical EngineeringPedagogical Engineering On-site training

5. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 5 Tutelvisio® (a distance learning service based on ISDN) « Student » studio: –Audio/video system (pan-tilt camera) controled by a specific software. –« Question & Answer » system controled and managed by specific software and hardware. « Lecturer » studio: –Audio/video system controled by a software. –a « user friendly » GUI for managing the lecture (interactivity, audio and video sources...) Softwares and protocols for controling the system and for communication between remote and Local site.

6. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 6 Tutelvisio® architecture * ISDN Internet H320 System 256 kbs H320 System MCU Audio system (microphones, speakers..) video system (pan/tilt cam. Monitor..) Audio system video system « user-friendly » Soft. « Student » studio « Lecturer » studio T2 Audio Video Data

7. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 7 A distance learning application : Visiocentre GUI

8. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 8 Remarks Benefits: –good video/audio quality (CIF/G711) and performances (throughput up to 768 Kbs) H320 QoS. drawbacks: –still some interoperability problems –difficult to deploy for individual or self training services –deployment cost

9. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 9 Tutelnet® (a distance learning tool based on Internet) * Internet Web server (Html+Smil) (Asynchronous web courses) Streaming server (live or stored Audio/Video sources) MCU Client (lecturer) Client (student) « TutelServer® »

10. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 10 Tutelnet® (components) WEB SERVER (HTML+SMIL): –contains Enic web courses for Asynchronous lectures (« Lecture On Demand ») STREAMING SERVER: –stored audio/video lectures for Asynchronous lectures (working with the web server) –live audio/video lectures for Synchronous lectures MCU : – multipoint videoconferencing for Synchronous lectures « TutelSERVER » : –specific multi-unicast software (JAVA) with enhanced services for Synchronous lectures (live « data » conferencing)

11. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 11 Components (continue) CLIENT: –client software (student) for accessing to « live » or « stored » lectures – client software (lecturer) for providing and managing live lectures »web browser »streaming client »H323 client » specific client (tutelbrowser®/tutelcast®)

12. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 12 Tutelcast® GUI (teacher point of view)

13. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 13 Tutelbrowser® GUI (student point of view)

14. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 14 G.U.I (for Voice/Video/Data integration)

15. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 15 Architecture (tutelnet®/tutelvisio®) Internet « CLIENT » (lecturer) « CLIENT» (student) ISDN H320 System 256 kbs H320 System MCU H320 H323/H320 Gateway + GateKeeper

16. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 16 Remarks Still some issues concerning interoperability (H323 systems). Strong issues concerning H323 through fire wall( open all UDP and TCP ports >1024). Heterogeneity in the access (Adsl, V90 modem, low bit rate modem, …) Today « our » Internet is not enough performant for supporting applications requiring interactivity »pstn access and phone for voice interactivity »internet only for data conferencing »streaming server for providing a « picture » of the lecturer Problem of servers load need « load sharing/balancing » between multiple servers and install the servers close to the client location. Ip address (clients) are dynamic and change very often. Control access is needed.

17. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 17 Mobility in the context of distance learning Lecturers may be in their office, lab or « outside », they want to be able to give their lectures from « anywhere » Students may be located at school, at home or at job office, they want to be able to access to live lectures or to a « Lecture on Demand » server Location of servers and content may change. Generaly outside university they have dynamic Ip adress from their ISP (DHCP) Ip address translation may occur through NAT.

18. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 18 SIP Protocol A good mean for dynamic ip address and clients mobility issues. Fields in SIP headers and « SDP » message body can provide a solution to describe the type of service the client wants to access »type of lecture and its identifier »start time »duration »... Provide enhanced services »forking, call forward... Can be used independantly of the media stream transfert protocol.

19. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 19 SIP Protocol (continue) RFC 2543 of the IETF MMUSIC Working Group. Signaling and call control protocol. Text oriented protocol (like Http, Smtp). Client/Server oriented protocol. Message strucure: »1 START LINE »2 HEADERS »3 BLANK LINE »4 MESSAGE BODY

20. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 20 Architecture for Sip (two new servers) * Internet Registar server database Sip proxy + redirect server + tutelServer® client

21. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 21 Different scenarios for distance learning services Scenario 1: access to a live/asynchronous lecture * Registar server database (registar.enic.com) Sip proxy.enic.fr + redirect server + tutelServer® database request(III) response (IV) Multi-unicast invite (V) (VI) data stream « a45live » @IP1 @IP2 @IP3 @IPn @IP2 @IP3 @IPn Clients @IP1 REGISTER sip:registar.enic.fr SIP/2.0 … subject=... content-type:application/sdp … v=0 o=« lecturer ’s name paul » s=« module n° a45live » t=« 2 h » …. (I) INVITE sip:a45live.enic.fr SIP/2.0 … …. (II)

22. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 22 Different scenarios for distance learning (cont.) Scenario 2: access to a stored/Asynchronous lecture(Lecture On Demand) Sip proxy + redirect server + tutelServer® Redirect server database INVITE sip:a45stored.enic.fr sip/2.0 … content-type:application/sdp.. O= P=0146532655... 302 moved contact: expires: 3600 content-type:application/sdp.. i=« Login/Pwd »... « smart load balancing » between servers and access control

23. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 23 Different scenarios for distance learning (cont.) Scenario 3: « access » to the lecturer at a clearly defined time (« tutorat ») * Lecturerpaul@office.enic.com Lecturerpaul@lab.enic.com Lecturerpaul@enst.paris.com Registar server Sip proxy + redirect INVITE sip:a45tut.enic.fr Fork the request to all possible location INVITE sip:lecturerpaul@lab.enic.fr INVITE sip:lecturerpaul@office.enic.fr INVITE sip:lecturerpaul@enst.paris.fr « client » student

24. A. MEDDAHI (TERENA Networking Conference 2001, ANTALYA, TURKEY 14~17 May) 24 Conclusion –SIP is not the only alternative H323, Megaco/h248... –Etablishment of users connections goes through sip proxy (it is not mandatory), provides some means for: acces control Log/Statistics –SIP is a « stand alone » protocole so it ’s possible to use it with any other media transfert protocols ( data transfert will be the first step, afterwards audio) –Minimal configuration is required from the client side. –Text oriented protocol facilitate understanding and implementation –Cohabitation and interworking with other signaling protocols (H323,H248…)? –This solution has to be fully validated.