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Abstract. Publish-subscribe systems are evolving toward using content-based subscription rather than subject-based subscription. A key problem in implementing such systems is that a straightforward mapping from matching sets to multicast groups produces a number of groups that rapidly grows beyond practical limits. This paper proposes a set of alternative algorithms for solving this problem, by: (1) using a smaller set of overbroad multicast groups, judiciously chosen to minimize imprecision; (2) issuing multiple multicasts to appropriately chosen clusters; or (3) sending an event over multiple hops each involving a multicast to a set of neighbors. We evaluate these algorithms on a simulated wide-area network. We find that (1) a simple flooding algorithm is viable over an extensive range of conditions; and (2) under conditions of high selectivity and high regionalism of subscriptions, the other approaches mentioned above perform significantly better; however, the specific algorithm to use depends upon the economics of deployment. 1

MD5 is an authentication algorithm proposed as the required implementation of the authentication option in IPv6. This paper presents an analysis of the speed at which MD5 can be implemented in software and hardware, and discusses whether its use interferes with high bandwidth networking. The analysis indicates that MD5 software currently runs at 85 Mbps on a 190 Mhz RISC architecture, a rate that cannot be improved more than 20-40%. Because MD5 processes the entire body of a packet, this data rate is insufficient for current high bandwidth networks, including HiPPI and FiberChannel. Further analysis indicates that a 300 Mhz custom VLSI CMOS hardware implementation of MD5 may run as fast as 256 Mbps. The hardware rate cannot support existing IPv4 data rates on high bandwidth links (800 Mbps HiPPI). The use of MD5 as the default required authentication algorithm in IPv6 should therefore be reconsidered, and an alternative should be proposed. This paper includes a brief description of the...

This paper considers the problem of providing transparent support for very large numbers of mobile hosts within a large internetwork such as the Internet. The availability of powerful mobile computing devices and wireless networking products and services is increasing dramatically, but internetworking protocols such as IP used in the Internet do not currently support host movement. To address this need, the Internet Engineering Task Force (IETF) is currently developing protocols for mobile hosts in the Internet. This paper analyzes the problem to be solved, reviews the current state of that effort, and discusses its scalability to very large numbers of mobile hosts in a large internetwork. 1.

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Current pricing and charging methods for the Internet are not based on actual usage of this service which leads to unfairness and more important, it does not deliver the right signals through financial incentives to network providers to upgrade critical links of their networks. The development of new multimedia applications and the convergence to an integrated services network will foster the tremendous growth of the Internet even more. With the Next Generation Internet not only technical services like bandwidth reservation will be introduced, but also new applications will emerge within the Internet. Charging the Internet in a fashion that provides feedback to users and providers has been proposed since the early `90s, however only a few implementations and real-world examples are known today. This is due to subsidizing the Internet in its early stages and due to a technical development that did not care much about charging. With the recent redesign of the Internet protocol suite and...

Quality of service of network video is determined by both the amount of available bandwidth and its temporal fluctuations. Except for the premium service, other proposed DiffServ traffic classes such as assured and best effort services are not immune to temporal bandwidth fluctuations. We observe that fluctuations in shared packet switching networks occur in different time scales, from less than a microsecond up to the order of minutes and longer. In the fast time scale #microseconds#, bandwidth fluctuations arecaused by bit errors, cell loss, and packet corruption, which are associated with noise in physical devices and communication channels. In the medium time scale #milliseconds to seconds#, fluctuations are often originatedfrom link layer operations such as routing, queueing, multiplexing and scheduling of communication links. In the slow time scale #seconds to minutes#, fluctuations are caused by connection migration among networks with diferent speeds #e.g. LAN vs. wireless#. While temporal fl#uctuation...

Migrating Sockets is the protocol processing component of an end system architecture designed for networking with QoS guarantees. The architecture provides (1) adaptive rate-controlled scheduling of protocol threads in Migrating Sockets, (2) rate-based flow control for reserved rate connections in future integrated services networks, and (3) a constant overhead active demultiplexing mechanism. Migrating Sockets achieves its efficiency by allowing user applications to manage a network endpoint with minimal system intervention, providing user level protocols read-only access to routing information in a "well-known" shared memory region, and integrating efficient kernel level support we previously built. It is backward compatible with Unix semantics and Berkeley sockets, and has been used to implement Internet protocols such as TCP, UDP and IP (including IP multicast). We also show that active demultiplexing supported by Migrating Sockets can be transparently enabled in wide-area TCP/IP internetworking (although it is not restricted to TCP/IP). We have an implementation of Migrating Sockets in Solaris 2.5. We discuss our implementation experience, and present performance results of our system running on the Ultra-1, SPARC 10 and SPARC 20 architectures.

This research investigates techniques for providing privacy, authentication, and data integrity to message passing in distributed applications. Various software mechanisms for message hashing and encryption are evaluated, including techniques for key generation and key distribution. Different crypto-APIs' are evaluated, and the distribution of a single session key for n-party communication is implemented. A secure version of PVM (Parallel Virtual Machine) is developed using Diffie-Hellman, MD5, and various symmetric encryption algorithms to provide message privacy, authentication, and integrity. The modifications to PVM are described, and the performance of secure PVM is evaluated.

Routers are key building blocks in networks. They need to cope with high data rates in the range of multiple gigabit per second that are flowing through them. Therefore, specifically performance critical functions should be implemented in dedicated hardware units in order to speed up the forwarding task. These units can be embedded within regular workstations or into dedicated router architectures. This paper we addresses one of the most performance critical components of a router, the routing table and its access and search mechanisms. Earlier work has shown that this is more critical with respect to the resulting performance than IP processing itself. A simple but efficient organization of the routing table using binary trees and off-the-shelf SRAMs is presented together with a suited search algorithm. Keywords: routing table, address lookup, ipv6 1. INTRODUCTION Multi-gigabit networks are under discussion since several years and their appearance seems just a matter of time. Pilot...