A Generic Proxy Mechanism For Secure Middlebox Traversal

Firewalls/NATs have brought significant connectivity problems along with their benefits, causing many applications to break or become inefficient. Due to its bi-directional communication, huge scale, and multi-organizational nature, the Grid may be one of the areas damaged most by the connectivity problem. Several ideas to deal with the connectivity problem were investigated and many systems are available. However, many issues still remain unanswered. Most systems are firewall/NAT unfriendly and are considered harmful to network security; the tussle between these devices trying to investigate payloads and applications trying to protect their content from observation and modification must be reconciled. This paper discusses how a simple relay-based system, called XRAY (middleboX traversal by RelAYing), deals with these issues and provides other benefits such as flexible traffic control. This paper also discusses how relay-based traversal systems can help applications to communicate over firewalls/NATs and also complement firewall/NAT operations to help network security.