Performance impact of data compression on virtual private network transactions

Virtual private networks (VPN) allow two or more parties to communicate securely over a public network. Using cryptographic algorithms and protocols, VPNs provide security services such as confidentially host authentication and data integrity. The computation required to provide adequate security: however, can significantly degrade performance In this paper we characterize the extent to which data compression can alleviate this performance problem in a VPN implemented with the IP Security protocol (IPsec). We use a system model for IPsec transactions to derive sm inequality that specifies the conditions requirement data compression to improve performance. We generate performances results for many combinations of network types, data types, packet sizes, and encryption, authentication and compression algorithms. We find? that compression usually improves performance when using 10 Mbps or slower networks, bur compression only improves performance ill systems with 100 Mbps or I Gbps network when using computationally intensive encryption algorithms.