Dynamic improvements for intelligent Performance Enhancement Proxy

While Performance Enhancement Proxy (PEP) is a promising solution for TCP´s performance issues over satellite links, it has a serious constraint in terms of a translation table limit of 500 entries that proved to be detrimental when a large number of TCP sessions need to be maintained between endpoints. We experienced one of these cases in Saudi Aramco where web-based drilling applications were establishing and maintaining large numbers of TCP sessions causing the PEP to hang and resulting in service interruptions, which is very costly in case of drilling rigs. To resolve this issue initially, an innovative idea to set timeouts on the TCP sessions that stay long enough to cause service interruptions was implemented. Since high data network reliability is a critical requirement for oil and gas rigs, this paper discusses the shortcomings of static timeouts and their implications. In addition, it suggests further enhancements for the PEP based on dynamic timeouts and a dynamic translation table size constituting a basis for the next generation intelligent PEP.