IJSRP, Volume 3, Issue 8, August 2013 Edition [ISSN 2250-3153]
Pratima Bhujbal, Uma Nagaraj
Now a days congestion in computer network is becoming an important issue. Variable-structure Congestion-control Protocol (VCP) and Double Packet Congestion Control Protocol (DPCP) operating in wireless networks are potentially faced with some challenges of performance degradation. These sources are: 1) The oscillatory behaviour of VCP in the presence of link bandwidth estimation errors is not good. 2) VCP exhibits poor fairness characteristics in high delay networks. 3) DPCP faces deployment obstacles in encrypted wireless networks due to the fact that it relies on partial information in the TCP header and the TCP header information is lost when crossing encryption boundaries. In this paper we propose an alternative congestion control protocol to which we refer as Enhanced Variable-structure Congestion-control Protocol for Encrypted Wireless (EVCP-EW) networks. It does so by passively utilizing the IP Identification field of a packet header instead of the TCP header in conjunction with a heuristic algorithm to differentiate between different sources of loss.