The application of header compression to IPsec encrypted networks

Abstract

As government networks migrate towards an Internet protocol version 6 (IPv6) based infrastructure, there is growing concern over the increased operational overhead required by IPv6 packets. IPv6 has twice the overhead of its predecessor, Internet protocol version 4 (IPv4), mainly due to a larger address space. Overhead concerns are further magnified in encrypted networks that employ IP security protocol (IPsec) tunnel-mode security associations (SAs). For example, global information grid (GIG) tactical networks, which are characterized by both bandwidth-constrained and high bit error rate (BER) links, may significantly be impacted by the additional IP header required by IPsec for traffic flow confidentiality. The Internet engineering task force (IETF) has developed various header compression algorithms to reduce the overhead associated with IP packets. Robust header compression (ROHC) and enhanced compression of the real-time transport protocol (ECRTP) mitigate the impact of the IPv6 overhead at the network layer, and help reduce overhead at the transport layer. In this paper, we evaluate the benefits of instantiating header compression in encrypted networks characterized by bandwidth-constrained, high BER links. The results will highlight the benefits of integrating ROHC and ECRTP with IPsec devices for compression of the plaintext upper layer protocols (ULP) headers of IP packets.