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VirtLan - network virtualization for educational purposes

There are two most common methods in situations, when there is a need to practically educate students in the area of computer networks and/or to perform some tests of network applications/protocols - appropriately equipped network laboratories or network simulators. While the network laboratories provide the most realistic sensation of the real networking nature, it lacks the scalability feature (in the sense of the number of students able to use it simultaneously) and provides limited flexibility (overcomed by financial/time investments only) and a difficult emulation of specific network states (packet losses, packet latencies, packet reorderings, etc.). On the other hand, the network simulators provide very high scalability and flexibility, as well as they easily allow the emulations of specific network states. However, the sensation of the real networking nature, including the possibilities of real-like network protocols/applications testing, is poor.

Fig. 1: The illustration of a virtual network definition in the proposed emulator.

Fig. 1: An illustration of a virtual network definition in the proposed emulator.

The goal of this project is to combine the positives of both the approaches and to propose and implement a novel network emulator framework allowing the definition of a virtual network (topology, network components, etc.) by the use of virtualized infrastructure - all the network components are provided by virtual machines (including the virtual network switches providing real-like switch controlling system) and the virtual network links are provided by point-to-point 802.1Q over 802.1Q virtual links - thus providing the following set of features:

the definition of various network topologies
in the users’ VMs (virtual computers/servers), the possibilitity to use all the user-defined top layers including the L3 ISO/OSI layer (the IP layer) - the emulator operates up to the L2 ISO/OSI layer
the possibilities to connect to all the defined network components (virtual computers/servers as well as switches) using a console and/or common connection methods (SSH, RDesktop, VNC, telnet, etc.)
the definition of various virtual network links’ parameters (including emulated latency, jitter, packet reorderings, links’ failures, etc.) as well as the possibilities to use pre-defined network links’ parameters (fiber links, metal links, wireless links, etc.)
the possibilities to define triggers and timed events in order to increase the debugability and reproducibility of the tests
and many others.

Fig. 2: An illustrated conversion of the example topology (Fig. 1) on the real virtualized substrate (including the illustration of the internal communication).

Fig. 2: An illustrated conversion of the example topology (Fig. 1) on the real virtualized infrastructure (including the illustration of the internal communication).

Contacts:
Tomáš Rebok, xrebok@fi.muni.cz