Standardized Bundle Agent Discovery on Delay/Disruption-Tolerant Networks

by Wyllie, James

Though copious networking research focuses on the terrestrial Internet, much of that research is not immediately applicable to devices in more "challenged" environments, such as deep-space probes and remote sensor networks. The communication channels between these devices may have any combination of extremely long round-trip times (on the order of seconds, minutes, or hours), low and unpredictable connectivity, asymmetric or unidirectional bandwidth, and a lack of an end-to-end path. To overcome these limitations, RFC5050 defines an overlay network, over which link-agnostic "bundles" are cached and transmitted by Bundle Agents (BAs) at key points in the network, much like e-mail messages. One key limitation of this mechanism is the lack of a discovery mechanism for "adjacent" BAs. To date, all inter-BA communication channels were either manually configured, or a one-off dynamic mechanism was created which was neither robust, portable, nor secure. This document defines a dynamic system, somewhat similar to both DHCP and IPv6 neighbor discovery, which is a combination of flexibility for diverse domains and generality for interoperability. Through demonstration and analysis, its effectiveness in implementation is also shown, as well as its relationship to BA routing. A discussion of relevant security issues and suggested mitigations is also presented.