Investigating the effects of security attacks on the performance of TCP variants and routing protocols in MANET

In mobile ad hoc networks (MANET), security attack due to malicious nodes can affect normal operation of routing protocols, performance of transmission control protocol (TCP), and the network at large. This paper has investigated the effects of packet drop attack on the performance of TCP variants and routing protocols. Simulation was conducted by adding different percentage of malicious nodes in the network. Results have shown that from TCP variants, Vegas outperformed Newreno and SACK with 0% malicious nodes. However, as the percentage of malicious nodes added in the network increases from 5% to 50%, Newreno and SACK performed better than Vegas. Moreover, ad hoc on-demand (AODV) is more robust to packet drop attack than dynamic source routing (DSR). Finally, we have proposed TCP-PLDR (Packet Loss Detection and Response technique), which differentiate packet loss due to congestion or malicious packet drop attack. Experimental results have shown that TCP-PLDR performed better than TCP-SACK.