1 MASTER THESIS QoS Estimation during Session Initiation of Video Streaming Session under the direction of Prof. Dr. Markuss Rupp DI Michal Ries Institut fur Nachrichtentechnik und Hochfrequenztechnik handed in Technischen Universitat Wien Fakultat fur Nachrichtentechnik und Hochfrequenztechnik by Iria Rodr´ıguez Escola T`ecnicaSuperior d´ Enginyeria de Telecomunicaci´ode Barcelona Universitat Polit`ecnicade Catalunya Matrikelnr: 0627627 Wien, July 2007 2 Executive Summary Executive Summary Purposes of the work The goal of this work is investigate the QoS provision mechanisms that can be used during the media session initialization, the translation of such mechanisms to Session Initiation Protocol an Session Description Protocol signalling and a physi- cal analysis task over an IMS testbed, that give rise to the knowledge of the current IMS deployment in this field. The steps followed to achieve this aim are divided in two different parts. The first part comprises a research study of 3GPP technical specifications and reports, recommendations, proposals, Request for Comments and all the literature involved. The second part deals with the comparison evalu- ation of theoretical supported and available mechanisms, architectures or designs in front of the physical development of all this aspects. The main contribution of this work is, therefore, an accurate State of Art about IMS QoS provision and a lack collection in the available IMS test tools. Organization of the work The outlines of the work have its basis on a decisive an deep research in the meaningful IMS signalling plane aspects and the IMS QoS Provision, with the final merging of both issues by means of Session Initiation Protocol and Session Description Protocol mechanisms for deal with media sessions ensuring QoS. In parallel, by means of the traffic generated in ftw's testbed and its proper analysis, is obtained a physical approach to the IMS QoS management. The confrontation of the two parts of the work reveals, finally, the current lacks and limitations (also due to the restrictions of the testbed itself) and makes feasible a suggestion phase for a proposal that ends in a new configuration of existing elements. Closes the work the set of conclusions that previous phases give rise to, just as other outputs that serve as subject for a new project/research. The final outline of the project and the chapters' organization is as follows: Executive Summary 3 Figure 1: Outline of the work 4 Contents Contents Executive Summary 2 Contents 4 List of Figures 9 List of Tables 11 I Research Work 13 1 Introduction 15 1.1 Outline: Understanding Concepts . 15 1.2 Perceptual QoS . 17 1.3 Multimedia Streaming Protocols . 18 1.3.1 Session Control: SIP . 18 1.3.2 Session Description: SDP . 18 1.3.3 Media Transport: RTP and RTCP . 19 1.4 Video Streaming Codecs over IMS . 20 1.4.1 H.263 . 21 1.4.2 MPEG-4 (Part 2) Simple Profile . 22 1.4.3 H.264 / MPEG-4 Part 10 AVC . 23 1.5 IMS Media Authorization . 24 1.6 End-to-End QoS Models: Resource Reservation . 24 1.6.1 Terminals Resource Reservation: PDP Context . 25 1.6.2 The Integrated Services Architecture: RSVP . 25 1.6.3 The Differential Service Architecture . 25 2 Video Session Initiation & QoS 27 2.1 Video Session QoS Requirements . 28 2.1.1 Key Performance Indicators . 30 5 6 Contents 2.2 General issues of end-to-end QoS . 31 2.2.1 Resource Check and IMS session setup . 31 2.3 QoS Concept and architecture in UMTS . 33 2.3.1 UMTS QoS Architecture . 34 2.3.2 UMTS Bearer Service Attributes . 35 2.4 Session setup procedures . 36 2.4.1 Codec negotiation . 38 2.4.2 Preconditions . 40 2.4.3 PDP Context Activation . 42 2.4.4 RSVP . 44 3 Policy-based QoS Control Scenario for IMS 47 3.1 Model for a policy-based network . 48 3.2 COPS Protocol over Go Interface . 50 3.3 The PEP in the GGSN . 50 3.3.1 Policy control: Requesting authorization . 51 3.3.2 Mapping/translation function . 52 3.4 Policy Decision Function (PDF) . 54 3.5 QoS Control Scenario for IMS Services . 55 4 SIP & SDP over IMS 57 4.1 SIP/SDP Overview . 57 4.1.1 SIP Overview . 57 4.1.2 SDP overview . 60 4.2 SIP/SDP and IMS . 62 4.2.1 Integration of Resource Management and SIP Preconditions RFC 3312 . 63 4.2.2 Media authorization RFC 3313 . 65 4.2.3 SDP Bandwidth Modifiers for RTCP Bandwidth (RFC 3556) . 66 4.2.4 Other extensions and constricts . 68 4.3 RTP/RTCP usage for video transport . 70 4.3.1 Picture Loss Indication . 71 4.3.2 Syncronization . 72 4.3.3 Video adaptation . 74 4.3.4 Video Bit Rate equalization in IMS - Circuit Switched interworking . 74 5 Session setup flows for QoS Provision 77 Contents 7 II Practical Work 91 6 Work environment 93 6.1 Previous: IMS Arquitecture . 94 6.2 Open Source IMS . 97 6.3 Looking for an IMS client . 102 6.4 Ethereal & SIP Scenario Generator . 104 6.4.1 Network Protocol Analyzer-tool: Ethereal . 104 6.4.2 Creating SIP Call Flows: SIP Scenario Generator . 105 7 Getting up and running the testbed 107 7.1 ftw testbed . 108 7.2 Client: IMS-Communicator . 108 7.2.1 Configuration . 108 7.2.1.1 Property: Preferred audio/video codec . 111 7.2.1.2 Transport protocol . 112 7.2.2 Starting the clients . 112 7.2.2.1 Registration . 112 7.2.2.2 Calling Process . 114 7.2.3 Other utilities . 114 7.3 Ethereal . 115 8 Testbed evaluation 117 8.1 Preconditions Support . 117 8.2 Codec Negotiation Procedures . 119 8.3 P-Access-Network-Info and Bandwidth Negotiation . 121 8.4 What is missing? . 121 8.5 Proposal:P-CSCF dealing with the precondition mechanism . 122 9 Conclusions 129 9.1 Achievements and Results . 129 9.2 Possible improvements . 130 III Appendix 131 A Summary: SIP & Session Negotiation 133 A.1 Preconditions (RFC 3312) . 133 A.2 Methods . 133 A.2.1 Options (RFC 3261) . 133 A.2.2 Negotiatie (Internet Draft) . 134 8 Contents A.3 Indicating User Agent Capabilities in the Session Initiation Protocol (SIP): SIP Capabilities (RFC 3840) & Caller Preferences for SIP (RFC 3841) . 134 A.4 SIP Headers . 136 A.4.1 P-Access-Network-Info (RFC 3455) . 136 A.4.2 P-Media Authorization (RFC 3313) . 136 A.4.3 Security Agreement (RFC 3329) . 137 A.5 SDP Simple Capability Declaration (RFC 3407) . 137 A.6 BW Negotiation . 138 A.7 Warning Codes (RFC 3261) . 138 B IMS-Communicator Configuration 145 B.1 Settings > Configure . 145 B.2 XML File . 155 C IMS-SIP Clients 161 D Captures & SIP Scenario Traces 165 D.1 Registration . 166 D.2 477 Error Message . 174 D.3 Basic Call: Alice − > Bob . 176 List of Abbreviations 200 Bibliography 204 List of Figures 1 Outline of the work . .3 2.1 UMTS QoS Arquitecture . 34 2.2 Basic video session flows . 37 2.3 Codec Negotiation . 39 2.4 Siganlling Flow using Preconditions . 41 2.5 PDP Context activation . 44 3.1 Functional entities involved in the policy-based QoS scenario . 49 3.2 QoS Control scenario for IMS . 56 4.1 Media Authorization Architecture . 65 5.1 General Flow . 78 5.2 (1) Invite . 79 5.3 (3) Invite . 80 5.4 Intermediate IM CN Subsystem entities flows . 81 5.5 Initial filter criteria . 82 5.6 (5) Invite . 83 5.7 (7) Invite . 84 5.8 (9) Session Progress . 85 5.9 (12) Session Progress . 86 5.10 (25) Update . 88 5.11 (29) 200 (OK) . 89 6.1 ims architecture . 94 6.2 Overview of IMS and NGN at FOKUS . 98 6.3 Open Source IMS Core in the Open IMS Playground . 99 6.4 Open Source IMS Core Components . 100 6.5 Ethereal panes . 104 6.6 Paquet details for a INVITE Request -Ethereal Capture- . 106 7.1 FTW testbed configuration . 108 9 10 List of Figures 7.2 IMS-Communicator: Registration . 113 7.3 FHoSS: User Profile . ..