Accommodating Network Evolution and Heterogeneity by Improving Network Transparency

Carnegie Mellon University, Pittsburgh PA

Investigators

Abstract

One of the core design principles of the Internet is the idea that it is sufficient for networks to implement a minimal set of functionality (the IP protocol) to allow networks to interoperate and any two nodes to communicate. However, many recent network technologies (e.g. wireless, long-latency and frequently-disrupted links) have been difficult to integrate into the Internet for this reason. This project explores two core techniques that enable better support for unusual links: explicit path queries and end-to-end adaptation. Internet support for explicit path queries would allow end-points to learn key properties of the links used for their communication. The i-Path system from Waseda University and AIST in Japan provides the foundation for this path query mechanism. New end-to-end adaptation mechanisms would allow end-points to adapt their behavior to the capabilities or quirks of the communication path. In particular, the project is modifying two end-point systems to react to path query results: 1) TCP congestion control and retransmission and 2) multimedia streaming applications. This effort is expected to show how such systems should adapt to the path properties, such as latency, bandwidth, loss rate, router buffering and in-network compression support. The broader impact of this work comes from showing that explicit path querying is critical for simplifying the addition of new technologies to the Internet. By lowering the bar for supporting link new technologies, this research enables a number of systems that will have significant social impact, such as sensors for elderly homecare, and delay-tolerant links to underdeveloped regions.