It is widely recognized that play is an important part of the learning process for children. There is also a nationwide gender gap in the fields of computer science and engineering. One identified reason for this gap is a lack of positive exposure to STEM activities for young girls. This paper explores workshops aimed at addressing the gender gap by leveraging playfulness. Specifically, two computer science workshops were deployed for young girls in fourth and fifth grade as part of a larger Girl Scouts of America initiative. These workshops embrace playfulness as a fundamental design constraint to ensure an early positive association with STEM concepts. Students are exposed to basic coding skills through simple robots that are programmed to play games. Survey results show that these workshops lead to a stronger interest in CS for the participants.

Numerous CS faculty have demonstrated the benefits of using version control in courses other than software engineering. However, they maintained their own servers, and to the best of our knowledge, none published experiences with version control in CS1 courses for non-CS engineering majors. As a result, even faculty experienced with version control may hesitate to adopt it in some classes, fearing that it is too difficult, time consuming or distracting. In this paper, we describe how we adopted version control in a CS1 course for non-CS engineering majors, and how software hosting services facilitated its use. Our experience indicates that undergraduate engineering majors in CS courses can gain competence in version control, and software hosting services simplify class administration.

Networking testbeds have become an increasingly important part of the networking research cycle. One of the primary reasons for this is that testbeds offer researchers access to network conditions and environments which are very difficult to reproduce in a local laboratory. This work presents the design of the Open Network Laboratory (ONL) testbed. The underlying infrastructure of ONL is general enough to support resource extensibility and heterogeneity at a fundamental level. New types of resources (e.g., multicore PCs, FPGAs, network processors, etc) can be added to the testbed without modifying any testbed infrastructure software. Resource types can also be extended to support multiple distinct sets of functionality (e.g., an FPGA might act as a router, a switch, or a traffic generator). Moreover, users can dynamically add new resource extensions without any modification to the existing infrastructure.

In recent years we have witnessed a proliferation of data structure and algorithm proposals for efficient deep packet inspection on memory based architectures. In parallel, we have observed an increasing interest in network processors as target architectures for high performance networking applications.

Over the last decade, programmable Network Processors (NPs) have become widely used in Internet routers and other network components. NPs enable rapid development of complex packet processing functions as well as rapid response to changing requirements. In the network research community, the use of NPs has been limited by the challenges associated with learning to program these devices and with using them for substantial research projects. This paper reports on an extension to the Open Network Laboratory testbed that seeks to reduce these "barriers to entry" by providing a complete and highly configurable NP-based router that users can access remotely and use for network experiments. The base router includes support for IP route lookup and general packet filtering, as well as a flexible queueing sub-system and extensive support for performance monitoring. In addition, it provides a plugin environment that can be used to extend the router's functionality, enabling users to carry out significant network experiments with a relatively modest investment of time and effort. This paper describes our NP router and explains how it can be used. We provide several examples of network experiments that have been implemented using the plugin environment, and provide some baseline performance data to characterize the overall system performance. We also report that these routers have already been used for ten non-trivial projects in an advanced architecture course where most of the students had no prior experience using NPs.

Virtual laboratories are a potential replacement for standard laboratory facilities. Use of these virtual resources can reduce cost and maintenance overheads for teaching institutions while still ensuring that students have access to real equipment. Previous work indicates that students respond well to such environments, but one important operational aspect has been overlooked. In this work, we consider instructor overhead by comparing the amount of work required to teach courses with and without the use of a virtual laboratory. In particular, we examine two graduate computer networking courses, each taught with the standard software-only approach and then taught later with the Open Network Laboratory. Our data show that the effort required by the instructor to use a virtual laboratory is not much more than in a software-only environment, and that the increased interaction between student and instructor can be beneficial as the student questions are primarily focused on fundamental networking concepts.

Modern high performance routers rely on sophisticated interconnection networks to meet ever increasing demands on capacity. Previous studies have used a combination of analysis and idealized simulations to show that coarse-grained scheduling of traffic flows can be effective in preventing interconnect congestion while ensuring high utilization. In this work, we study the performance of a coarse-grained scheduler in a real router with a scalable architecture similar to those found in high performance commercial systems. Our results are obtained by taking fine-grained measurements within the router that provide a detailed picture of the scheduler's behavior under a variety of conditions, giving a more complete and realistic understanding of the short time-scale dynamics than previous studies could provide.

In recent years, overlay networks have become an important vehicle for delivering Internet applications. Overlay network nodes are typically implemented using general purpose servers or clusters. We investigate the performance benefits of more integrated architectures, combining general-purpose servers with high performance Network Processor (NP) subsystems. We focus on PlanetLab as our experimental context and report on the design and evaluation of an experimental PlanetLab platform capable of much higher levels of performance than typical system configurations. To make it easier for users to port applications, the system supports a fast path/slow path application structure that facilitates the mapping of the most performance-critical parts of an application onto an NP subsystem, while allowing the more complex control and exception-handling to be implemented within the programmer-friendly environment provided by conventional servers. We report on implementations of two sample applications, an IPv4 router, and a forwarding application for the Internet Indirection Infrastructure. We demonstrate an 80x improvement in packet processing rates and comparable reductions in latency.

The Open Network Laboratory (ONL) is a remotely accessible network testbed of high performance routers which has been designed with an eye towards ease of use for users from the naïve to the expert. The system is built around a set of high-performance routers that are extendible and easily configurable through the Remote Laboratory Interface (RLI), an intuitive graphical interface. The RLI also makes it easy to configure packet filters in the routers, assign flows or flow aggregates to separate queues with configurable QoS and attach hardware monitoring points to real-time charts. The RLI’s real-time charts and user data facility makes it easy to directly view the effects of traffic as it moves through a router, allowing the user to gain better insight into system behavior and create compelling demonstrations. Each port of the router is equipped with an embedded processor that supports software plugins which allow users to extend the system’s functionality. This paper describes the ONL and how it can be used in networking education. You should checkout our web site onl.arl.wustl.edu which includes a short video.