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As the technology used to implement computer network infrastructure advances, networking resources are becoming more vulnerable to attack. Recent router designs are based on general-purpose programmable processors, which increase their potential vulnerability. To address this issue, a Secure Packet Processing platform has been developed that can flexibly protect emerging router systems. Both instruction-level operation of embedded processors and I/O operations of router ports are monitored to detect anomalous behavior. If such behavior is detected, a recovery system is invoked to restore the system into an operational state. Experimental results show that processor-based attacks can generally be determined by a processing monitor within a single instruction. I/O anomalies, including unexpected packet broadcast or delay, can be detected by an I/O monitor with limited overhead. Overall, the system overhead for secure monitoring is limited to a fraction of the overall system space, memory, and power budget.

PC-based software routers are major and common network elements of today's Internet infrastructure. In this paper, we model and analyze the performance of PC-based software routers. Our model adopts realistic assumptions of using finite queues and multi-phase services. Specifically, we model a router with two interfaces as two finite queueing systems in tandem with the first queueing system being a two-stage service and the second queueing system being a single-stage service. The two-stage service consists of a first stage in which data-link layer functionalities are performed, and a second stage in which forwarding/routing functionalities are performed. In this paper, we verify and validate our analytical model by using simulation and real experimental measurements obtained from a PC router with two interfaces. In addition, we discuss how our analytical models can be used to analyze a router with multiple interfaces. From our models, we derive equations for key features and performance measures of engineering and design significance. These features and measures include throughput, packet loss, packet delay, average number of packets in the queues and in the overall system, and CPU utilization and availability.

One of the most active research areas in networking is quality of service (QoS). The most fundamental requirement for QoS is the ability to find a path that can provide the required network resources between two nodes. These nodes will use QoS routing to find a feasible QoS path between both of them. In this paper, we present a distributed multicast QoS routing architecture that uses probes to find a quick and scalable QoS path between a joining router and the multicast tree. Any router that receives this probe will only know its neighbours and it will create a link to the previous router from where the probe comes from. The joining router will join the multicast tree by following these links on each router until it reaches the tree. Analysis of this method shows that the convergence rate and message overhead is lower than other similar schemes.

Although the majority of the traffic over the Internet is still TCP-based, applications such as voice over IP and video-conferencing are changing this very rapidly. While TCP-based applications react to network congestion, UDP-based streaming applications usually do not have any type of flow and congestion control mechanisms. UDP, the transport layer protocol used by audio and video streaming applications, does not react to network congestion thus stealing bandwidth from the responsive TCP-based connections. Several solutions have been suggested to combat this TCP-friendliness problem, mostly applied either in the end systems (end-to-end) at the transport layer of the protocol stack or inside the network (routers) at the network layer. This article surveys the state-of-the-art in router-based mechanisms to address the TCP-friendliness problem and presents a description of the most important algorithms, design issues, advantages and disadvantages, and a performance evaluation. The article also describes ways to estimate the number of active flows traversing a core router and points to further sources on this subject, which is widely used by many mechanisms, including several described in this survey.

This paper presents a parallel Internet router that supports the integration of the ATM (Asynchronous Transfer Mode) and IPv6. The hardware architecture and the software algorithms of the parallel router are discussed. The key concept of the proposed parallel hardware is to have one routing node to be responsible for one network link to achieve a high packet switching speed. The packets are switched through the communications among the routing nodes. Each routing node is constructed by a general-purpose computer plus an inter-node communication unit (ICU), and an intelligent network interface. The ICU developed in this work segregates realtime and non-realtime packets to support the ATM/IP integration. The ICU also self-manages the buffer memory address accesses and the burst packets produced by the variable rate realtime communications to reduce the CPU workload and in return to increase the switching bandwidth. An ATM-cell/IPv6-packet co-switching/routing mechanism has been developed for the router control software based on the hardware architecture of the proposed parallel router.

This paper presents a new, flexible approach to inter-domain multicast routing. The HIP protocol introduces the idea of ''virtual routers'' as a method of organizing the control of an entire domain so as to appear as a single router on a higher-level shared tree. HIP then routes between domains using the Ordered Core Based Tree (OCBT) protocol, and allows recursive application of virtual routers to create a multi-leveled hierarchy while providing efficient methods of distributing the location of the center point for the tree. The advantages of this approach include improved robustness, the ability to route between heterogeneous domains and a significant reduction in the amount of bandwidth consumed in control traffic and in the amount of state stored at each router over existing hierarchical multicast protocols.