Gda´nsk University of Technology Faculty of Electronics, Telecommunications and Informatics Department: Computer Communications Author: Tomasz Mrugalski Studies type: Ph.D. Studies Ph.D. Dissertation Dissertation topic: Optimization of the autoconfiguration mechanisms of the mobile stations supporting IPv6 protocol in the IEEE 802.16 environment Polish title: Optymalizacja mechanizm´ow automatycznej konfiguracji stacji ruchomych wspierajacych, protok´o lIPv6 w ´srodowisku sieci IEEE 802.16 Supervisor: prof. dr hab. in_z. J´ozef Wo´zniak Gda´nsk, 2009-10-19 ii Contents List of Figures ix List of Tables xiii Polish Extended Abstract xvii I. Wprowadzenie........................................... xvii I.1. Prze laczenie, w warstwie IEEE 802.16.......................... xvii I.2. Rekonfiguracja IPv6.................................... xviii I.3. Metryka HD........................................ xx I.4. Teza pracy......................................... xx II. Przeglad, literatury......................................... xxi II.1. WiMAX Forum....................................... xxi II.2. Grupy robocze IETF.................................... xxi II.3. Uznane standardy..................................... xxi II.4. Niezale_zne propozycje................................... xxiii III. Propozycje usprawnie´n....................................... xxiii III.1. U_zycie istniejacych, optymalizacji............................. xxiii III.2. Propozycje autorskie.................................... xxiv III.3. Ominiecie, oczekiwania wstepnego, w DHCPv6...................... xxiv III.4. Ominiecie, wykrywania zduplikowanych adres´oww IPv6................ xxiv III.5. Wykrywanie zduplikowanych adres´owpo stronie serwera................ xxv III.6. Zdalna autokonfiguracja poprzez DHCPv6........................ xxv III.7. Konfiguracja routingu poprzez DHCPv6......................... xxv III.8. Zdalne uaktualnienie powiaza´nw, Mobile IPv6..................... xxv IV. Analiza wydajno´sci......................................... xxvi IV.1. Model symulacyjny..................................... xxvi IV.2. Generatory liczb pseudolosowych............................. xxvi IV.3. Metodologia obr´obki wynik´oweksperyment´ow..................... xxvi IV.4. Dane empiryczne...................................... xxvii IV.5. Symulowane scenariusze.................................. xxvii IV.6. Eksperymenty symulacyjne................................ xxviii IV.7. Przeprowadzone badania.................................. xxix IV.8. Transmisja i modele ruchu................................. xxix IV.9. Czas przygotowania do prze laczenia, ........................... xxx IV.10. Czas ponownego wej´scia do sieci............................. xxx iv CONTENTS IV.11. Czas rekonfiguracji stosu IPv6.............................. xxx IV.12. Czas konfiguracji DHCPv6................................ xxx IV.13. Przerwa w zdolno´sciach komunikacyjnych........................ xxxi V. Wnioski i rezultaty......................................... xxxi V.1. Dibbler { implementacja DHCPv6............................ xxxii V.2. Numbat { ´srodowisko symulacyjne............................ xxxiii 1. Introduction 1 1.1. WiMAX Overview.........................................1 1.1.1. MAC messages and CS sublayer.............................3 1.1.2. Initial Network Entry...................................3 1.1.3. Handover Process.....................................4 1.1.4. Neighbor Advertisements.................................4 1.1.5. Scanning..........................................5 1.1.6. 802.16 Handover......................................6 1.1.7. Network reentry......................................6 1.2. IPv6 Overview...........................................7 1.2.1. IPv6 addressing.......................................8 1.2.2. IPv6 reconfiguration....................................9 1.2.3. IPv6 interface reinitialization...............................9 1.2.4. Automatic configuration in IPv6.............................9 1.2.5. Router Discovery...................................... 10 1.2.6. DHCPv6.......................................... 10 1.2.7. Duplicate Address Detection............................... 11 1.2.8. Mobile IPv6 Overview................................... 12 1.3. Mobile WiMAX/IPv6 convegence................................. 12 1.3.1. Multi-layer handover procedure.............................. 13 1.4. Thesis................................................ 13 1.4.1. Research goals....................................... 13 1.4.2. Handover Delay metric.................................. 14 1.5. Terminology notice......................................... 15 2. Related work 17 2.1. WiMAX Forum........................................... 17 2.2. IETF working groups....................................... 18 2.3. Mobile IPv6............................................. 18 2.4. Fast Handovers for Mobile IPv6.................................. 19 2.5. Hierarchical MIPv6......................................... 20 2.6. Route Optimization in Mobile IPv6 using Static Shared Key................. 21 CONTENTS v 2.7. Enhanced Route Optimization for MIPv6............................ 21 2.8. Mobility support in DHCPv6................................... 22 2.9. Optimistic DAD.......................................... 23 2.10. IEEE 802.21............................................. 24 2.11. IEEE 802.16e (Mobile WiMAX)................................. 25 2.12. 802.16 extensions.......................................... 25 2.13. Independent proposals....................................... 25 2.13.1. An Improved FHMIPv6 Handover for Mobile WiMAX................. 25 2.13.2. New Handover Mechanism for 802.16e Networks.................... 26 2.13.3. Roaming Over WLAN and WiMAX........................... 26 2.13.4. Seamless Realtime Traffic Handover Policy for IEEE 802.16m............. 27 2.13.5. Human Mobility Patterns................................. 27 2.13.6. Mobile networks on Vehicles across Heterogeneous Networks.............. 27 2.13.7. Fast RSVP reservation for Mobile IPv6......................... 28 2.14. Summary.............................................. 28 3. Proposed improvements 31 3.1. Existing features usage....................................... 31 3.1.1. WiMAX Optimizations.................................. 31 3.1.2. DHCPv6: Preference 255................................. 34 3.1.3. DHCPv6: Rapid-commit................................. 35 3.2. New improvement proposals.................................... 36 3.2.1. Skip initial delay in DHCPv6............................... 36 3.2.2. Skip Duplicate Address Detection in IPv6........................ 37 3.2.3. DHCPv6: Server side Duplicate Address Detection................... 38 3.2.4. Remote Autoconfiguration via DHCPv6......................... 40 3.2.5. Routing configured via DHCPv6............................. 43 3.2.6. Mobile IPv6: Remote Binding Update.......................... 44 4. Efficiency analysis 49 4.1. Simulation model.......................................... 50 4.1.1. Simulation length time................................... 50 4.1.2. Numbat overview...................................... 51 4.1.3. 802.16 PHY profile..................................... 52 4.1.4. Mobility model....................................... 54 4.1.5. Traffic models........................................ 55 4.1.6. Limitations......................................... 56 4.2. Random numbers generators................................... 57 4.2.1. Mersenne Twister..................................... 58 vi CONTENTS 4.2.2. PRNG Sequence length.................................. 59 4.2.3. Assured simulations independence............................ 60 4.3. Experiment results methodology................................. 60 4.3.1. Selecting sample sizes................................... 60 4.3.2. Warm-up period...................................... 61 4.3.3. Trend estimation...................................... 63 4.4. Empirical data........................................... 66 4.4.1. DHCPv6 measurements: the Dibbler project...................... 66 4.4.2. Mobile 802.16 Base Station hardware.......................... 67 4.5. Simulated scenarios......................................... 67 4.5.1. Scenario 1: No optimization................................ 68 4.5.2. Scenario 2: 802.16e optimization............................. 69 4.5.3. Scenario 3: DHCPv6: Skip initial delay......................... 69 4.5.4. Scenario 4: DHCPv6: Preference 255........................... 69 4.5.5. Scenario 5: DHCPv6: Rapid-commit........................... 69 4.5.6. Scenario 6: IPv6: Skip DAD............................... 69 4.5.7. Scenario 7: DHCPv6: Server side DAD......................... 70 4.5.8. Scenario 8: DHCPv6: Remote configuration....................... 70 4.5.9. Scenario 9: DHCPv6: Address parameters........................ 70 4.5.10. Scenario 10: Mobile IPv6: Remote Binding Update................... 70 4.6. Experiments............................................. 70 4.6.1. Experiment 1: Downlink measurements......................... 71 4.6.2. Experiment 2: Uplink measurements........................... 72 4.6.3. Experiment 3: IPv6 and DHCPv6 configuration.................... 72 4.6.4. Experiment 4: Handover Preparation and Delay.................... 73 4.7. Traffic impact assessment..................................... 73 4.7.1. Downlink traffic...................................... 73 4.7.2. Uplink traffic........................................ 76 4.7.3. Traffic