Measurement Based Analysis of the Handover in a WLAN MIPv6 Scenario Albert Cabellos Aparicio, René Serral-Gracià, Lorand Jakab, Jordi Domingo-Pascual Universitat Politècnica de Catalunya Departament d Arquitectura de Computadors acabello@ac.upc.edu
Introduction Objectives Methodology Results Conclusions Outline
Introduction: Motivation 802.11 provides wireless connectivity to the IP provides mobility to the IPv6 jointly with 802.11 provides wireless mobility to the The handover is the most critical part During this phase, the mobile node is not able to send or receive data, and some packets may be lost or delayed
802.11 SCAN PHASE
802.11 SCAN PHASE 1.- Point found!
1.- Point found!
1.- Point found!
1.- Point found!
802.11 REGISTRATION AUTHENTICATION PHASE 1.- Point found!
802.11 REGISTRATION AUTHENTICATION PHASE 1.- Point found! 2.- MN connected to AP
1.- Point found! 2.- MN connected to AP
1.- Point found! 2.- MN connected to AP
Advertisement 1.- Point found! 2.- MN connected to AP
Advertisement 1.- Point found! 2.- MN connected to AP Neighbor Unreachability Detection
Advertisement Duplicate Address Detection 1.- Point found! 2.- MN connected to AP Neighbor Unreachability Detection
Advertisement Duplicate Address Detection 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete Neighbor Unreachability Detection
1.- Point found! 2.- MN connected to AP 3.- IPv6 complete
1.- Point found! 2.- MN connected to AP 3.- IPv6 complete
Binding Update Binding Ack. 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete
Binding Update Binding Ack. Binding Update Binding Ack. 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete
Binding Update Binding Ack. Binding Update Binding Ack. 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete 4.- Handover complete!
1.- Point found! 2.- MN connected to AP 3.- IPv6 complete 4.- Handover complete!
1.- Point found! 2.- MN connected to AP 3.- IPv6 complete 4.- Handover complete!
DATA 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete 4.- Handover complete!
DATA 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete 4.- Handover complete! MOVEMENT
DATA 1.- Point found! 2.- MN connected to AP 3.- IPv6 complete Start the whole process 4.- Handover complete! AGAIN MOVEMENT
Introduction Objectives Methodology Results Conclusions Outline
Objectives Create a structured methodology to study the handover: Passive measurements Analyze the handover latency Compare different handover layers Active measurements Packet Losses The effects of the handover on traffic sent or received by applications Apply this methodology to study the WLAN/IPv6/ in a real scenario.
Introduction Objectives Methodology Results Conclusions Outline
Handover 802.11/IPv6/MIPv6 Signaling messages Methodology: Passive Measurements Monitor Point PHM Tool Monitor Point Results MOVEMENT
PHM Tool Methodology: Passive Measurements Input Captured frames from both s. Currently supports: MIPv6 IPv6 Very easy to extend! FH 802.11 MIPv4 IPv4
Methodology: Active Measurements Goal Compute the Packet Losses Compute OWD and IPDV before/after the handover Differentiate between the wireless part and the wired part How Using Active and Passive Measurements Sending a synthetic flow and capturing it on the s and on the destination Computing the (above mentioned) parameters of the synthetic flow We use NetMeter for this purpose
Methodology: Active Measurements
Methodology: Active Measurements
Methodology: Active Measurements Synthetic Flow (one direction)
Methodology: Active Measurements Monitor Point Monitor Point Synthetic Flow (one direction) Monitor Point
Methodology: Active Measurements Monitor Point Monitor Point Synthetic Flow (one direction) Monitor Point
Methodology: Active Measurements Monitor Point Monitor Point Monitor Point
Methodology: Active Measurements Synthetic Flow (one direction) Monitor Point Monitor Point Monitor Point
Methodology: Active Measurements Synthetic Flow (one direction) Monitor Point NetMeter Monitor Point Monitor Point Results
Methodology: Active Measurements NetMeter Provides an integrated graphical interface for a set of tools that allows the measurement Sets up the sender and the receiver Supports MGEN/MGEN6 NetPerf Supports different types of graphics Can use multiple capture points providing partial delays.
Methodology: Tests All the machines synchronized (1ms accuracy) 16 tests each 5 minutes long, in total 63 handovers CN MN MN CN 64Kbps UDP traffic (34 pps, 252 bytes) 1Mbps UDP traffic (94 pps, 1300 bytes)
Introduction Objectives Methodology Results Conclusions Outline
Results: Handover Latency Mean Std. Dev. Scan 257.224 108.007 Authentication 2.733 1.183 Association 1.268 0.311 IPv6 1863.413 430.196 Registration (HA) 3.914 1.1017 Registration (CN) 9.262 4.881 Total Time 2107.82 450.619 Values in ms
Results: OWD and IPDV
Results: OWD and IPDV
Results: PL, OWD and IPDV Packet Loss Mean Std. Dev. 64Kbps 1Mbps 64Kbps 1Mbps MN CN 65.80 162 9.78 16.97 CN MN 61.71 207.21 17.54 65.90 OWD and IPDV OWD (ms) IPDV (ms) Before After Before After 64Kbps (VoIP) 54.08 53.25 0.0125 0.0096 1Mbps 63.58 28.51 7.2566-0.0011
Introduction Objectives Methodology Results Conclusions Outline
Conclusions Our analysis focuses on all levels involved in the handover process We have developed a structured methodology to study the handover process in a real scenario Our methodology is very easy to extend to other protocols Our study of the 802.11/IPv6/ shows that: The handover latency is (aprox.) 2 seconds Most of the time is spent in the IPv6 handover Packet Loss = rate x handover latency
Thank you! Available at http://www.ccaba.upc.edu/netmeter PHM Tool Soon available at http://www.ccaba.upc.edu
Importance of the Medium Algorithm