CURRENT_MEETING_REPORT_ Reported by Isidro Castineyra/Bolt Beranek and Newman Minutes of the New Internet Routing and Addressing Architecture Working Group (NIMROD) Preface The NIMROD Working Group met on Tuesday, 4 April, and on Wednesday, 5 April. The agenda for the meeting was: o Tuesday - Agenda bashing/Announcements - Overview of the Deployment Document (Charlie Lynn) - Configuration vs. Discovery (Martha Steenstrup) - Discussion o Wednesday - What is in the Nimrod Model (Martha Steenstrup and Isidro Castineyra) - Software Architecture (Charlie Lynn) - Discussion - Open Issues and Work Plan Deployment Document Charlie Lynn gave an overview of the Deployment Document. He discussed strategies for the gradual integration of Nimrod in the Internet. Configuration vs. Discovery Martha Steenstrup presented a list of information elements that could be obtained by either configuration or discovery. For each element, Martha discussed the trade-offs and the current thoughts on what to do with that element. Highlights of her presentation follow. o The goal is to make both a ``plug-and-play'' system and to make everything configurable. o Configured items: - At Node Representatives: adjacency formation constraints, association constraints, set of locator elements for component nodes. - At Endpoint Representatives: EIDs and names of endpoints, association constraints, multicast group membership of endpoints. - At Forwarding Agents: traffic restrictions. - At Agents: type of agent, EID of agent, nodes on which behalf the agent acts (configured). Martha will be posting the slides she used to the working group mailing list. Nimrod Model/Bootstrap I Isidro Castineyra described a bootstrap model for Nimrod. Highlights of his talk follow: o Nimrod specifies only what happens between nodes. o The internal operation of an ``atomic'' node is not Nimrod's concern. o There are two kinds of locators: flat and hierarchical. o The flat locator of a node is used in Basic Routing (later) to do flat routing within the components node of nodes. This mode of routing is used to bootstrap hierarchical routing. o The Nimrod part of a hierarchical locator is a sequence of up to 256 locator elements, where a locator element is a 16-bit string. o Hierarchical locator is ``inside'' a node if its Nimrod part is both prefixed by the node's locator and longer than the node's locator. o For a given node and for a given hierarchical locator inside the node, the first element following the original node's locator identifies a component node. This 16-bit string is referred to as the node's ``local element.'' Therefore, nodes are limited to having no more than 216 component nodes. o For a given node, the assignment of the values of local element to component nodes is independent both of assignment of local elements inside the node's subnode and in nodes that subsum the given node. o Basic routing is based only on connectivity (i.e., it does not take into account considerations of quality of service or service restrictions). o Basic routing is used for agent discovery and to enable communication between agents that reside in different nodes. The advanced routing capabilities of Nimrod are built over basic routing. o Basic routing is very much like a one-level OSPF. Basic routing is built over a flooding protocol which works between the set of nodes. When a message is flooded, every node in the set receives a copy of the message which is delivered to the node's representative(s). o Information flooded includes: identity of neighboring component nodes, what agents the node includes. Slides from this presentation will be posted to the mailing list. Nimrod Model/Bootstrap II Martha Steenstrup described an alternative bootstrap model. Highlights of her presentation follow: o Besides interaction between nodes, Nimrod specifies interaction between agents within a node. These agents might reside in separate ``boxes'' and be connected via IP. o Agents need not reside in the node on whose behalf they act. o Agents advertise their presence and characteristics using a reliable hop-by-hop flooding protocol. This flooding is used to construct a next-hop agent forwarding table using an algorithm similar (but not identical) to standard distance vector algorithms. The slides for this presentation will be sent to the mailing list. Software Architecture Charlie Lynn presented the current software architecture for the BBN implementation of Nimrod. Path Management Issues Martha Steenstrup listed alternatives for path setup. o Should path labels be globally unique or path unique. o Path constructions: should we use hierarchical routes or hierarchical paths. o Path repair: should it be done at any node; at initiator or target; between successive hops?