A mobile ad hoc Network (MANET) is a collection of wireless mobile nodes forming an infrastructure less network that has no centralized manager.In such a network,topology changes because of limitation on immportant issues like as mobility,bandwidth and transmission range and battery power.One of most well known routing protocol is Dynamic Source Routing (DSR) that provides simple routing for ad hoc networks.Due to dynamic properties of ad hoc networks and specially,DSR routing,introduced methods to increasing throughtput and better balancing in traffic loads,that called multipath routing.multipath routings build multiple paths between resource node and its destination that it is typicalli proposed in order to increase the reliability of data transmission or provide load balancing and improve some QoS metrics; otherwise,the performance of routing protocols will significantly degrade,if there are faulty nodes in the network.There are numerous multipath routing protocol developed based on DSR that use Partially-Disjoint or Fully-Disjoint Routing metrics to improve base routing protocol.We study the performance of DSR ans some extented protocols such as SMR,M-DSR ans SMS,and then aim to show not always maximally disjoint routing is a perfect solution,but a loosely disjoint path could sometime be acceptable.