Berkeley Software Distribution

Abstract: Packet forwarding for OSI poses strong challenges for routing lookups: the algorithm must be able to efficiently accommodate variable length, and potentially very long addresses. The 4.3 Reno release of Berkeley UNIX† uses a reduced radix tree to make decisions about forwarding packets. This data structure is general enough to encompass protocol to link layer address translation such as the Address Resolution Protocol (ARP), and the End System to Intermediate System Protocol (ES−IS), and should apply to any hierarchical routing scheme, such as source and quality-of-service routing, or choosing between multiple Datakits on a single system. The system uses a message oriented mechanism to communicate between the kernel and user processes to maintain the routing database, inform user processes of spontaneous events such as redirects, routing lookup failures, and suspected timeouts through gateways.

Abstract: This document describes the observed behavior of the syslog protocol. This protocol has been used for the transmission of event notification messages across networks for many years. While this protocol was originally developed on the University of California Berkeley Software Distribution (BSD) TCP/IP system implementations, its value to operations and management has led it to be ported to many other operating systems as well as being embedded into many other networked devices.

Abstract: The 4.2 Berkeley Software Distribution of the Unix operating system (4.2BSD for short) features an extensive body of software based on the "TCP/IP" family of protocols. In particular, each 4.2BSD system "trusts" some set of other systems, allowing users logged into trusted systems to execute commands via a TCP/IP network without supplying a password. These notes describe how the design of TCP/IP and the 4.2BSD implementation allow users on untrusted and possibly very distant hosts to masquerade as users on trusted hosts. Bell Labs has a growing TCP/IP network connecting machines with varying security needs; perhaps steps should be taken to reduce their vulnerability to each other.

Abstract: UC (UNIX Consultant) is an intelligent, natural language interface that allows naive users to learn about the UNIX2 operating system. UC was undertaken because the task was thought to be both a fertile domain for artificial intelligence (AI) research and a useful application of AI work in planning, reasoning, natural language processing, and knowledge representation.The current implementation of UC comprises the following components: a language analyzer, called ALANA, produces a representation of the content contained in an utterance; an inference component, called a concretion mechanism, that further refines this content; a goal analyzer, PAGAN, that hypothesizes the plans and goals under which the user is operating; an agent, called UCEgo, that decides on UC's goals and proposes plans for them; a domain planner, called KIP, that computes a plan to address the user's request; an expression mechanism, UCExpress, that determines the content to be communicated to the user, and a language production mechanism, UCGen, that expresses UC's response in English.UC also contains a component, called KNOME, that builds a model of the user's knowledge state with respect to UNIX. Another mechanism, UCTeacher, allows a user to add knowledge of both English vocabulary and facts about UNIX to UC's knowledge base. This is done by interacting with the user in natural language.All these aspects of UC make use of knowledge represented in a knowledge representation system called KODIAK. KODIAK is a relation-oriented system that is intended to have wide representational range and a clear semantics, while maintaining a cognitive appeal. All of UC's knowledge, ranging from its most general concepts to the content of a particular utterance, is represented in KODIAK.