Network policy languages: a survey and a new approach

TLDR

Network policy languages range from low‑level packet filters to high‑level abstract concepts, with policy frameworks and routing protocols discussed. The paper surveys existing network policy languages, reviews conflict‑detection techniques, and introduces a new path‑based policy language. The authors survey current languages, summarize conflict‑detection techniques, and present the design of a path‑based policy language. The path‑based policy language associates QoS and security policies with explicit network paths, supports integrated services, and can be relaxed with wildcards to accommodate differentiated and best‑effort services.

Abstract

A survey of current network policy languages is presented. Next, a summary of the techniques for detecting policy conflicts is given. Finally, a new language, path-based policy language, which offers improvements to these is introduced. Previous network policy languages vary from the very specific, using packet filters at the bit level, to the more abstract where concepts are represented, with implementation details left up to individual network devices. As background information a policy framework model and policy-based routing protocols are discussed. The PPL's path-based approach for representing network policies is advantageous in that quality of service and security policies can be associated with an explicit path through the network. This assignment of policies to network flows aids in new initiatives such as integrated services. The more stringent requirement of supporting path-based policies can easily be relaxed with the use of wild card characters to also support differentiated services and best-effort service, which is provided by the Internet today.