30-05-2012, 11:13 AM
A Packet Forwarding Mechanism for MANET using
MODRP in Dynamic Source Routing (DSR)
A Packet Forwarding Mechanism for MANET.pdf (Size: 427.29 KB / Downloads: 26)
Abstract-
An ad hoc network is a collection of computers
(nodes) that cooperate to forward packets for each other over a
multihop wireless network. Users of such networks may wish to
use demanding applications such as Voice over IP,
videoconferencing, and streaming media when they are
connected through an ad hoc network. Because over
provisioning, a common technique in wired networks, is often
impractical in wireless networks for reasons such as power, cost,
and government regulation, Quality of Service (QoS) routing is
even more important in wireless networks than in wired
networks. Though a number of QoS-routing protocols have been
proposed for use in ad hoc networks, security of such protocols
has not been considered.
INTRODUCTION
Mobile Ad hoc NETworks (MANET), are characterized by
wireless nodes, which are free to move arbitrarily, but
cooperate to forward packets for each other in a totally
wireless environment.
The routing requirement of a mobile ad hoc network is
achieved in distributed fashion among the nodes. Various
route discovery protocols have been designed for mobile ad
hoc networks. Like other multi-hop networks, there are two
phases of MANET operations: the route discovery phase and
data transmission phase [5]. Routing protocols are responsible
for the route discovery phase. However, since the data
transmission phase solely depends on paths discovered in the
route discovery phase, it is imperative to look into the data
transmission Phase as a logical next step of route discovery.
DYNAMIC SOURCE ROUTING PROTOCOL DETAILS
The Dynamic Source Routing (DSR) protocol is a distancevector
routing protocol for MANETs. When a node generates
a packet to a certain destination and it does not have a known
route to that destination, this node starts a route discovery
procedure. Therefore, DSR is a reactive protocol [3].
The DSR protocol requires each packet to carry the full
address (every hop in the route), from source to the
destination. This means that the protocol will not be very
effective in large networks, as the amount of overhead carried
in the packet will continue to increase as the network.
COMMON SECUTIRY ATTACKS
The nodes of a MANET are actually mobile routers that
build up routes dynamically. These routers can move
randomly and insert themselves automatically into dynamic
wireless topologies. They perform packet forwarding using
the current routing information[12]. A path form the source to
the destination, that is, a route, can be established through
well known routing protocols such as the ad hoc on-demand
distance vector routing (AODV), dynamic source routing
(DSR), temporally ordered routing algorithm (TORA), zone
routing protocol (ZRP), and destination sequenced distancevector
(DSDV). Selfish and malicious nodes take advantage
of Manet’s idiosyncrasies to misbehave, or attack [12].
CONCLUSION
Ad-hoc networks are frequently targeted by participating
malicious nodes to sabotage the network. A common
mechanism to protect these networks is through the use of
encryption and hashing mechanisms. However, the
implementation of these mechanisms generally imposes
certain unessential requirements, which are considered as
restrictive for unplanned environments. In this paper we have
discussed the dynamic trust based approach through which
association between nodes are used to resist selective packet
drop attacks connected to adhoc networks