A Cisco Education Tool Accessible to the Vision Impaired
J. Hope, B. R. von Konsky, I. Murray, L. C. Chew, B. Farrugia · 2006 · Proceedings of the 8th International ACM SIGACCESS Conference on Computers and Accessibility (Assets '06) · doi:10.1145/1168987.1169032
Summary
This paper describes iNetSim, a universally accessible network simulator developed at Curtin University of Technology to allow vision-impaired and sighted students to complete Cisco Certified Network Associate level 2 (CCNA 2) laboratory sessions. The standard Cisco learning tool, Packet Tracer, is a Macromedia Flash application that relies on images of network topology to display information, making it completely inaccessible to screen readers. iNetSim was built on Mac OS X Tiger (10.4), chosen because it included VoiceOver, a system-wide screen reader with full computer functionality, and the Cocoa API for rapid application development with built-in accessibility support. The simulator represents network devices (routers, switches, hubs, PCs) with configurable ports of different types (Ethernet, serial, console). Users create connections by specifying two ports and a cable type, and can remove connections in the same way. A command line interface provides control over the simulation, acting like a DOS-like system for PCs or Cisco IOS for routers, supporting commands for device configuration, routing protocols, ping, traceroute, and telnet. All user interface and network topology elements are reachable with VoiceOver keys and provide meaningful responses when read by VoiceOver. iNetSim uses tables rather than graphical icons for connecting devices and configuring the topology, making it fully keyboard-navigable.
Key findings
A totally blind user successfully completed two CCNA 2 laboratories in beta testing, even though he was unfamiliar with the material, and reported being impressed with iNetSim's ease of use. Verification of the final interface using the Accessibility Verifier tool revealed only minor issues — missing AXDescription descriptors — which were trivial to fix. The authors note that while automated accessibility checking tools exist, they vary in completeness (how many accessibility checkpoints are covered), correctness (false positive rate), and specificity (number of distinct issues detected), and that involving representative users in field testing, prototyping, and evaluation is essential for achieving genuine usability. The sighted GUI provides an alternative drag-and-drop mouse-based interface, allowing both user groups to use the same tool. The authors conclude that assistive design choices made early in development led to a better quality product overall — the constraints imposed by screen reader compatibility required a well-designed graphical user interface that benefited all users.
Relevance
This paper addresses a practical and significant accessibility barrier in IT professional education. Cisco certifications are among the most widely pursued credentials in networking, and inability to access the training tools effectively excludes vision-impaired students from an entire career path. The project demonstrates that accessible alternatives to visual simulation tools can be built when accessibility is considered from the start of development. The choice of Mac OS X with VoiceOver as a development platform — leveraging built-in accessibility infrastructure rather than retrofitting — is a pragmatic lesson in platform selection for accessible software development. The finding that building for accessibility produced a better overall product echoes a core principle of universal design. The work also highlights a recurring problem in STEM education: professional training tools and simulations are frequently built with exclusively visual interfaces, creating barriers that are unnecessary given that the underlying concepts (network configuration, routing, device management) are fundamentally non-visual and can be expressed through text and structured data.
Tags: visual impairment · education · screen reader · VoiceOver · network simulation · STEM accessibility · universal access · IT certification