Policy issues in interconnecting networks

To support the activities of the Federal Research Coordinating Committee (FRICC) in creating an interconnected set of networks to serve the research community, two workshops were held to address the technical support of policy issues that arise when interconnecting such networks. The workshops addressed the required and feasible technologies and architectures that could be used to satisfy the desired policies for interconnection. The results of the workshop are documented

Hierarchical Inter-Domain Routing Protocol with On-Demand ToS and Policy Resolution

Traditional inter-domain routing protocols based on superdomains maintain either ``strong'' or ``weak'' ToS and policy constraints for each visible superdomain. With strong constraints, a valid path may not be found even though one exists. With weak constraints, an invalid domain-level path may be treated as a valid path. We present an inter-domain routing protocol based on superdomains, which always finds a valid path if one exists. Both strong and weak constraints are maintained for each visible superdomain. If the strong constraints of the superdomains on a path are satisfied, then the path is valid. If only the weak constraints are satisfied for some superdomains on the path, the source uses a query protocol to obtain a more detailed ``internal'' view of these superdomains, and searches again for a valid path. Our protocol handles topology changes, including node/link failures that partition superdomains. Evaluation results indicate our protocol scales well to large internetworks. (Also cross-referenced as UMIACS-TR-94-73

The Viewserver Hierarchy for Inter-Domain Routing:Protocols and Evaluation

We present an inter-domain routing protocol based on a new hierarchy, referred to as the viewserver hierarchy. The protocol satisfies policy and ToS constraints, adapts to dynamic topology changes including failures that partition domains, and scales well to large number of domains without losing detail (unlike the usual scaling technique of aggregating domains into superdomains). Domain-level views are maintained by special nodes called viewservers. Each viewserver maintains a view of a surrounding precinct. Viewservers are organized hierarchically. To obtain domain-level source routes, the views of one or more viewservers are merged (upto a maximum of twice the levels in the hierarchy). We also present a model for evaluating inter-domain routing protocols, and apply this model to compare our viewserver hierarchy against the simple approach where each node maintains a domain-level view of the entire internetwork. Our results indicate that the viewserver hierarchy finds many short valid paths and reduces the amount of memory requirement by two orders of magnitude. (Also cross-referenced as UMIACS-TR-93-98.1

Research summary, January 1989 - June 1990

The Research Institute for Advanced Computer Science (RIACS) was established at NASA ARC in June of 1983. RIACS is privately operated by the Universities Space Research Association (USRA), a consortium of 62 universities with graduate programs in the aerospace sciences, under a Cooperative Agreement with NASA. RIACS serves as the representative of the USRA universities at ARC. This document reports our activities and accomplishments for the period 1 Jan. 1989 - 30 Jun. 1990. The following topics are covered: learning systems, networked systems, and parallel systems