Ralph E. Droms

Automated configuration of TCP/IP with DHCP

The TCP/IP suite has various protocols that must be carefully configured so that networked devices operate efficiently. Setting values by hand is time-consuming and error-prone; moreover, several trends are adding to the need for automated parameter configuration and administration. The Dynamic Host Configuration Protocol, accepted as a proposed standard by the Internet Engineering Task Force, offers a way to automatically configure network devices that use TCP/IP. These devices use DHCP to locate and contact servers, which return the appropriate configuration information as data. The DHCP servers act as agents for network administrators and automate the process of network address allocation and parameter configuration. Addresses can be assigned and individual addresses can be reassigned to new DHCP clients without explicit intervention by a network administrator. The IETFs Dynamic Host Configuration (DHC) working group is now at work adding new features to DHCP. The author describes the groups work on DHCP in detail, outlines the management of a DHCP service, and discusses new DHCP features, including the version being developed for IPv6.1089-7801/ 9 9/

Access to heterogeneous directory services

10.00 ©1999 IEEE IEEE INTERNET COMPUTING A utomatic configuration for networking follows naturally from the more traditional uses of automatic configuration in standalone computers. A good example of standalone use was the “autoconf ” feature delivered with UC Berkeley’s versions of the Unix operating system. Since then, there have been more ambitious attempts to supply so-called “plug-n-play” (or, as often, “plug-n-pray”) features for commodity laptop operating systems. The problem for network computing, however, is made immeasurably more complex by the proliferating numbers of computers on the Internet and the possible interactions among them. The need for autoconfiguration is brought about by several factors, including:

Uniform access to Internet directory services

A description is given of the directory access service (DAS), which automates the process of searching multiple directories. DAS is directory service user interface that integrates the various directories into a single, uniform directory service. In response to a user query, DAS forwards queries to multiple directories. The responses are collected and formatted by DAS into a standard format for presentation to the user. The design of DAS is flexible and extensible, allowing convenient integration of new directories into DAS as they become available.<<ETX>>

A uniform interface to networked library services

As networks and internetworks of computers expand in size and scope, discovery and location of resources becomes a primary function of the networked computing environment. Static tables describing network resources have been replaced by dynamic directory services, such as X.500 and the Internet Domain Name System. These dynamic directory services provide more timely and accurate information about network resources than static tables. A wide variety of services address various components of the resource discovery and location problem. These services can be loosely classified as either low-level protocols or high-level services. Low-level protocols, such as RARP and ICMP, are simple delivery protocols and provide limited information; high-level services, such as the Internet Domain Name System and X.500, use complex delivery protocols to answer complex queries. Neither class of directory service is appropriate in all situations. Low-level services are too restrictive in the type of queries and information they support, while high-level services may be too expensive for some low-function networks.

Report from the joint SIGGRAPH/SIGCOMM workshop on graphics and networking

The expansion of the Internet haa &ouSht many new *S of network services to Internet users. One such aetvice is the online library catalos system. A lack of standsrds for the storage and retrieval of bibliographic information has resulted in a wide variety of incompatible user interfaces and formats for the presentation of such information. This paper is a comprehensive study of the libraty catalos systems currently available and a proposal for a homogeneous interface to these heterogeneous catalog systems.

Consequences of IPv6 Addressing

1. I n t r o d u c t i o n On January 16-18, 1991, SIGGRAPH and SIGCOMM held a joint workshop in Boulder, CO, on the interaction between computer graphics and computer networking. The purpose of the workshop was to bring together experts in the fields of graphics and networking to promote the study of the ways in which distributed, graphics-based applications interact with network services. The workshop was organized as a result of discussions between Vint Cerf, chair of SICGCOMM, Jim Thomas, chair of SIGGRAPH, and Craig Partridge, also of SIGCOMM, who explored the need for dialogue between those working in computer graphics and networks. As a result of these discussions, Partridge and Thomas laid the groundwork for the workshop and asked Bob Haber of SIGGRAPH and Ralph Droms of SIGCOMM to act as co-chairs. The National Center for Atmospheric Research (NCAR) graciously, offered the use of their facilities for the workshop, and the workshop was held at NCAR in Boulder. The workshop included 32 participants from both the United Kingdom and the United States, representing a full spectrum of academic, research, government and commercial organizations.

Performance measurements of the X window system communication protocol

The IETF has proposed a set of protocols known collectively as IPv6 to serve as the next generation of Internet Protocols. IPv6 provides Internet-layer services with functionality similar to that of IPv4, but changes many details of addressing and address assignment. This paper argues that the proposed changes will result in a significant redefinition of the existing Internet model, and will have substantial impact on higher layer protocols, especially applications. The paper also discusses ways in which the negative effects can be ameliorated; however, none of the available solutions can completely solve the problems introduced by the changes to the Internet addressing model.