1. Remo Cocco, Malik Ahmed, Dan Urbano, and Vasil Hnatyshin Department of Computer Science Rowan University

2. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

3. But first…  We would like to congratulate Dr. VH  He will be honored in the Ki Delta’s Pi International Honor Society 100 th anniversary book  It features stories about teachers who have inspired students  The story will be read on March 8 th at KDP’s Founder’s Day celebration

4. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

5. Routing – An Overview  What’s the problem?  The Source Node (S) wants to send information to the Destination Node (D).  Where does S send its packets of information to in order for the packets to end up at D? R2 S R4 R3 R1 D

6. Routing – An Overview  Solution – Keep a forwarding table  Source Node S keeps information about where to send the packets to so that they end up at Destination D.  Node S looks up this information inside its forwarding table when it is about to send out packets. R2 S R4 R3 R1 D

7. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

8. Routing – Forwarding Table  A Simplified Version of a Forwarding Table  Each entry has the following fields:  Destination IP Address  Destination Sequence Number  Next Hop Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1 Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1 Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1 Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1

9. R2 S R4 R3 R1 D Routing – Forwarding Table  S refers to D by its IP address. D’s IP address = 150.250.1.1  The following entry tells S who to send the next packet to. Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1 Destination IP Address Destination Sequence # Next Hop 209.85.148.105123456150.250.190.1 150.250.1.1178965150.250.190.1 209.191.122.70224870150.250.190.1

10. Routing – Forwarding Table  Here’s Another Problem:  How does the information get in the forwarding table to begin with?  The Solution  Routing protocols will find routes from a source to a destination.  These protocols will fill in the information in the forwarding table.

11. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

12. Mobile Networks  The mobile networks we will be teaching today are known as MANETs  Mobile Ad-hoc NETworks  Mobile – the nodes of the network can move  Ad-hoc – does not rely on existing infrastructure  Network – a collection of computers (nodes) connected by communication channels  Example: disaster relief – the infrastructure was wiped out but the need for communication exists  Since devices are mobile and can move freely, each device must be able to find new routes itself.

13. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

14. Mobile Networks – Some Semantics  Node  A computer which must route all messages wirelessly through other nodes  Nodes can move around  You can think of nodes as laptops or cell phones that can not use a radio tower to get a signal  Neighboring Nodes  Any two nodes which can directly communicate with each other  Unicast, Multicast, Broadcast  Visualizations of each of these are on the following slides.  Flooding  A large number of packets flow through the network that can cause congestion

15. Packet For Node X Mobile Networks – Some Semantics  Unicast  Delivers a message to a single specified node.  Here is an example of sending a unicast message: Packet For Node X Packet For Node X Packet For Node X Packet For Node X Packet For Node X Packet For Node X

16. Packet For Nodes X,Y,Z,T Mobile Networks – Some Semantics  Multicast  Delivers a message to a group of nodes that expressed interest in receiving the message.  Here is an example of flooding a multicast message: Packet For Nodes X,Y,Z,T Packet For Nodes X,Y,Z,T

17. Packet For All Nodes Mobile Networks – Some Semantics  Broadcast  Delivers a message to all of the nodes in the network.  Here is an example of flooding a broadcast message: Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes Packet For All Nodes

18. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

19. Mobile Networks: Reactive Vs Proactive  Routing protocols are needed to find routes between a source node and a destination node  Reactive – “I need to send information to another node but I don’t have a route yet! I will find one.”  Proactive – “I just entered a network. Before I even begin to send information, I’m going to find a route to every other node in the network just to be prepared ahead of time.”

20. Mobile Networks: Reactive Vs Proactive Reactive  Only calculate new routes when they are needed  Do not maintain routes to every node in the network  Also known as On Demand Routing  Efficient for low mobility, light traffic networks.  Examples  DSR  AODV Proactive  Try to calculate all of the routes beforehand  Actively maintain updated routes to every node in the network  Also known as Table Driven Routing  Incurs overhead when the network changes  Examples:  IS-IS  OSPF

21. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

22. AODV Routing d – Hoc  Does not rely on pre-existing infrastructure n – Demand  A reactive protocol – only create routes on demand istance ector AA OO DD VV Vector  Distance Vectors are used to calculate routes from one mobile node to the next since routers are not used in an ad-hoc protocol

23. AODV Routing  Designed for mobile networks holding hundreds of nodes where all nodes trust each other.  Used to find a route from a source node to a destination node when no current path is known.  Does this problem sound familiar?

24. AODV Routing TThe Problem From Before: HHow does the information describing the route from source node to destination get into the forwarding table to begin with? TThe Solution From Before: RRouting protocols will find routes from a source to a destination and will fill in the information in the forwarding table. TThis is the job of AODV!

25.  The basic idea when source S has a route to destination D  The forwarding table at S declares to who send the packets to in order to eventually reach D.  A unicast message is sent from S to that intermediate node.  Lots of uninterested nodes will receive the message but only the particular intermediate node it was designated for will continue to send the packets along to other nodes in the same manner until the packets reach D

26. AODV Routing  The basic idea when source S does not have a route to destination D  S sends out a multicast control packet called RREQ, or “route request” to all neighboring nodes.  Each neighbor checks to see if it is actually the destination or if it has a route to the destination.  If not, send out another RREQ to their own neighbors. This is called flooding.  If any node receives an RREQ and is the destination or has a route to it, send back a unicast RREP, or “route reply” control packet to the node that sent the RREQ.

27. AODV Routing  Route Discovery Process via flooding. RREQ for Node D RREQ for Node D RREP for Node S RREP for Node S RREP for Node S

28. AODV Routing  The New Route

29. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

30. Routing Table  A Simplified Version of a RoutingTable  Each entry has the following fields:  Destination IP Address  Destination Sequence Number  Network Interface  Next Hop  Hop Count  Lifetime Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021 Destination IP Address Destination Sequence # Network Interface Next HopHop CountLifetime 209.85.148.105123456eth0150.250.1.114126 150.250.190.204178965eth0150.250.190.132544 209.191.122.70224870wlan0150.250.1.1121021

31. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

32. RREQ – Route Request  An RREQ is made up of the following fields:

33. RREQ – Route Request Hop CountID NumberDestination IP Address Destination Sequence # Originator IP Address Originator Sequence # 112345209.191.122.7055150.250.190.204126 Each node asks, “Do I have a path to destination?” “No.” Increment hop count and re-broadcast. Hop CountID NumberDestination IP Address Destination Sequence # Originator IP Address Originator Sequence # 112345209.191.122.7055150.250.190.204126 Hop CountID NumberDestination IP Address Destination Sequence # Originator IP Address Originator Sequence # 212345209.191.122.7055150.250.190.204126 Any nodes that have seen this RREQ before ignore it. Hop CountID NumberDestination IP Address Destination Sequence # Originator IP Address Originator Sequence # 312345209.191.122.7055150.250.190.204126 “Oh, wait, I am the destination!”

34. RREQ – Route Request  Each node can use the IP Datagram that was wrapped around the RREQ packet.  Each node can pull the IP address of the last node that sent the RREQ.  Each node now knows that in order to send a reply back to Source S, the next hop must be that guy and it knows the hop count too from the RREQ packet.  D now knows who to send to in order to reach S.  D now sends a unicast RREP back to that guy, with intentions of reaching S to let S know everything’s OK

35. RREP – Route Reply  An RREP is made up of the following fields:

36. RREQ – Route Request The Destination now sends a reply back to the source. The Source has successfully received the RREP packet. Information from the packet can be used in the source’s routing table, such as ‘3 hops to reach D’ and the ‘next hop to reach D’ which it can pull from the IP Datagram of the RREP it just received.

37. Topics  Routing – An Overview  Forwarding Table  Mobile Networks  Some Semantics  Reactive vs Proactive  AODV Routing  Routing Table  RREQ and RREP  Location-Aided Routing

38. Location Aided Routing (LAR)  AODV creates unnecessary overhead when RREQ packets flood the entire network.  LAR aims to reduce this overhead by only allowing packets to propagate towards the destination.  LAR can use Global Positioning System (GPS) to determine the direction to send packets.

39. Location Aided Routing (LAR)  Knowledge of each node’s physical location at some previous point in time will help send packets in the right direction.  LAR does NOT use directional antennae.  Instead, upon receiving an RREQ with additional positional information, each node will determine if it is “in the right direction” of the destination.  If so, the node will re-broadcast the packet.  If not, the node will ignore it, saving on overhead.

40. Location Aided Routing (LAR)  LAR Scheme 1  Knowing the average velocity (v) at which the destination is moving, we can draw a circle around the last known destination’s coordinates with radius v.  The destination is likely to be in this circle.  We will box this circle as sown:  Only nodes inside this box will continue to broadcast the packet.

41. Location Aided Routing (LAR)

42.  LAR Scheme 2  LAR Scheme 2 does not rely on velocities of nodes.  The source can send out the destination’s last known coordinates in the RREQ packet along with its own.  Any node that receives the RREQ and is closer to the destination then the last sender of the RREQ should re-broadcast the RREQ with its own coordinates attached.

43. Location Aided Routing (LAR)

44. Geo AODV  Our research was to improve on an idea for a better LAR algorithm.  A better algorithm will cause less overhead in an AODV network.  Former Rowan students, working with Dr. VH, developed an algorithm, Geo AODV.  We analyzed the algorithm and put it to the test against other LAR algorithms.

45. Geo AODV  Geo AODV defines an initial “flooding angle” from the source aimed towards the destination.  The cone-shaped figure might make for a more accurate bounds to the actual path from S to D then a rectangle.  Any node inside the cone will rebroadcast the RREQ.  Any node outside will ignore it.

46. Implementation  We used OPNET 16.0 to implement the different routing protocols in order to observe the results.

47. Testing  The whole point of Location Aided Routing is to reduce the number of messages being broadcast.  This cuts down on overhead  This allows the network to process more requests in a shorter period of time  We tested 2 schemes against regular AODV and looked at the number of RREQs being generated

48. Results

49. References  http://ntrg.cs.tcd.ie/undergrad/4ba2.05/group11/index.html http://ntrg.cs.tcd.ie/undergrad/4ba2.05/group11/index.html  http://wiki.uni.lu/secan-lab/Reactive+Routing.html http://wiki.uni.lu/secan-lab/Reactive+Routing.html  http://wiki.uni.lu/secan-lab/Proactive+Routing.html http://wiki.uni.lu/secan-lab/Proactive+Routing.html