We have conducted a performance study of the DSR protocol, in particular, for scenarios where it presents poor performance compared to that of AODV protocol. We have also carried out two optimizations on DSR, namely: generalized salvaging mechanism and cache update of the intermediate nodes with source routes discovered during the route request packets propagation. Our routing protocol, called GSM-DSR (generalized salvaging mechanism for DSR), is compared with AODV and DSR, and performance results are presented in this paper. We show, through simulations, that the salvaging optimization and the cache update do lead to an improvement of DSR performance, particularly, in large scale networks with high mobility and heavy load.