Analysis of Inconsistent Routing Components in Reactive Routing Protocols Habib-ur Rehman, Lars Wolf Institut für Betriebssysteme und Rechnerverbund Technische Universität Braunschweig WMAN 2009, 5 th March, Kassel
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Outline Introduction How to Improve Reactive Routing? The Problem: Use of Prior-to-demand Collected Routing Data?? Analysis of AODV Objectives and Nature of Analysis AODV-TTL AODV-RS Simulation Setup/Results Conclusions IBR, TU Braunschweig 2/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras How to Improve Reactive Routing? • Reactive Routing • On-demand operations • High Response Time • Connection set up/recovery • Typical Approach • Use prior-to-demand collected routing data • Share more-than-demanded routing data • route request/reply packets carry additional data • Collect more-than-required routing data • overhear the routing packets for others • Use in route interruptions or subsequent route discoveries IBR, TU Braunschweig 3/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Use of Prior-to-demand Collected Routing Data • Examples • DSR maintains alternate routes by overhearing routing packets • AODV uses previously known hop-count in new route discoveries • Overhearing: a common practice among multiple path protocols • For example: AOMDV, AODV-BR • An Inconsistent Approach • No proactive mechanism to refresh stored routing data • Due to ever changing topology future and fortune of such acts • Totally dependent on network and topology conditions • Unpredictable and volatile behavior/effects/benefits IBR, TU Braunschweig 4/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras This Paper • Analyze: use of prior-to-demand collected routing data • Understand the effect on • Protocol operations • Protocol/Network performance • Approach • Analyze the deviation in the behavior of a reactive routing protocol after • Increasing the use of previously collected routing data • Decreasing the use of previously collected routing data IBR, TU Braunschweig 5/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Analysis • Standard AODV vs. two modified versions • AODV-TTL • less dependent on previously collected routing data • more reactive • AODV-RS • shares more routing data for subsequent use • subsequent actions: less reactive • Compared performance metrics • MAC overhead • Routing overhead • Data packet delivery ratio • Route discovery time IBR, TU Braunschweig 6/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras AODV-TTL • Expanding ring search during the route discovery • TTL field determines how many hops a RREQ will travel • In AODV: in case of an existing entry • TTL = last known hop count + TTL_INCREMENT > TTL_START • In AODV-TTL • TTL = TTL_START • Route recovery or route discoveries: completely on-demand IBR, TU Braunschweig 7/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras AODV-RS • Routing messages carry the information on two nodes only • The originator and the previous hop • Route Sharing • Include all the nodes along the path into a RREQ/RREP message • In AODV-RS • every intermediate node appends its previous hop • shares ample amount of prior-to-demand routing data • effect the subsequent actions IBR, TU Braunschweig 8/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Simulations • OPNET Modeler • manet_station node model • Random way point mobility • Simulation scenarios • Varying network size and data streams • Varying mobility parameters Sim ulation settings for Sim ulation Scenarios Pause Tim e, Node Speed and Packet Rate Data Active Nodes Area Variation Pause Tim e Node Speed Data Packet Rate Stream s Nodes of (seconds) (m / sec.) (packets/ second) 800 m 5 8 0, 30, 60, 300, 25 X Pause Time 1 4 900, 1800 20 20 800 m Node Speed 0 1, 2, 5, 10, 25 4 2000 m 20 30 100 X 80 85 Packet Rate 0 1 1, 2, 5, 10, 20 500 m IBR, TU Braunschweig 9/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Results: MAC Overhead MAC Ov e rh e ad (2 5 n o de s 5 stre am s) 395.8248 388.3791 384.4953 400 • AODV-RS 320 • 2-20 % higher packets (x 10 0 0 ) • AODV-TTL 240 • 1-11 % less 160 80 0 A ODV -RS AODV A ODV -TTL MAC Ov e rh e ad (10 0 n o de s 8 0 stre am s) 3000 2481.7781 2500 2052.8417 packets (x 10 0 0 ) 1847.5576 2000 1500 1000 500 0 AODV -RS AODV AODV-TTL IBR, TU Braunschweig 10/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Results: Routing Overhead Ro u tin g Ov e rh e ad (2 5 n o de s 5 s tre am s ) 20 17.8699 • AODV-RS 17.5296 17.3544 16 • 2-20 % higher packets (x 10 0 0 ) • AODV-TTL 12 • 1-11 % less 8 • Quite similar to MAC overhead 4 • In reactive routing protocols, 0 Routing traffic dictates the AODV-RS A ODV AODV-TTL overhead Rou t i n g Ov e r h e a d (10 0 n od e s 80 s t r e a m s ) 625 559.4331 462.4367 500 416.193 packets (x 10 0 0 ) 375 250 125 0 A ODV-RS A ODV A ODV -TTL IBR, TU Braunschweig 11/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Results: Overhead • Why the packet overhead is high in AODV-RS? • Higher initial value of TTL • Less controlled flooding • Higher contribution of RREP messages • More nodes are able to respond during route discovery Percentage of RREQ and RREP packets AODV-RS AODV 25 nodes 5 stream 82.42 8 1.73 25 nodes 20 streams 80.53 77.6 9 Initial value of the TTL field RREQ 100 nodes 20 streams 78.10 75.8 9 AODV-RS AODV 100 nodes 80 streams 77.84 72.69 25 nodes 5 stream 1.21 25 nodes 5 stream 13.53 1.69 13.6 6 25 nodes 20 streams 1.52 25 nodes 20 streams 17.10 2.27 18 .32 RREP 100 nodes 20 streams 1.81 100 nodes 20 streams 18.59 3.0 3 21.73 100 nodes 80 streams 2.56 100 nodes 80 streams 19.29 4 .77 25.34 IBR, TU Braunschweig 12/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Results: Packet Delivery Pa ck e t De l i v e r y Ra t i o (25 n od e s 5 s t r e a m s ) 0.9803 0.9706 1 0.9609 • Data Packet Delivery Ratio • AODV-RS 0.9 • 1-10 % less 0.8 • AODV-TTL 0.7 • 1-8 % higher • Higher overhead 0.6 • causes more saturation A ODV -RS AODV A ODV -TTL • results in less throughput Pa ck e t De l i v e r y Ra t i o (10 0 n od e s 80 s t r e a m s ) 1 0.9 0.8277 0.8 0.7594 0.6834 0.7 0.6 A ODV -RS A ODV A ODV -TTL IBR, TU Braunschweig 13/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Results: Route Discovery Rou t e Di s cov e r y T i m e (25 n od e s 5 s t r e a m s ) 0.42 • Route Discovery Time 0.3947 0.4 0.3929 • Inconclusive 0.3809 0.38 s econ ds • 802.11 is a contention-based MAC 0.36 • AODV-RS 0.34 • 3 % less in (25 nodes 5 streams) scenario 0.32 • 2-6 % higher in others AODV-RS A ODV A ODV -TTL • RREP requires RTS/CTS exchange Rou t e Di s cov e r y T i m e (10 0 n od e s 20 s t r e a m s ) • AODV-TTL 1.2 • 1 % less in (100 nodes 20 streams) 1.1587 1.16 scenario • 0.5-3 % higher in others 1.12 s econ ds 1.0953 1.0831 • Requires more expansion steps of 1.08 ring search 1.04 1 AODV -RS AODV AODV-TTL IBR, TU Braunschweig 14/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Conclusions • More prior-to-demand routing data present in the network • Less RREQs but more RREPs • AODV loses the benefit of expanding ring search • suffers due to higher TTL • More overhead • AODV-RS > AODV > AODV-TTL • Less packet delivery ratio • Mainly due to higher overhead, contention • Route discovery time • unpredictable in contention based scenarios IBR, TU Braunschweig 15/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Conclusions • Expanding ring search without exceptions • Less overhead • Higher route discovery time • Sharing more routing data: Not a good approach • Higher overhead • Collecting more routing data might work in some cases IBR, TU Braunschweig 16/17 Inconsistent Reactive Routing Components
Introduction Analysis AODV-TTL AODV-RS Simulations Results Conclusions Extras Thank you very much for your attention Questions/Comments/Suggestions
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