Network Emulator with Virtual Host and Packet Diversion

When developing new network protocols, new functionalities of network devices, new traffic models and other novelties, we face the problem of non-existing tools. If we want to simulate the behavior of the network with a newly developed feature we have to develop a new simulator or add a new functionality to an existing simulation tool. Both options can be quite complex and/or time consuming. To facilitate the testing and simulation of a new packet scheduler that we developed during our research we have developed a simulator for a general model of a network device. For this purpose we have used the Modular Simulation language, MODSIM III. It is a general-purpose, modular, block structured language that provides support for object-oriented programming, discrete event simulation and animated graphics. The simulator includes modules for the most important elements and functions of a packet network device, modules for collection of results, and modules for writing the results into a standard format files. We have tested and validated the operation of the simulator with analytically verifiable settings. The simulation and analytical results were practically the same. Encouraged with that we have then simulated newly developed packet schedulers and network device functionalities. Some of the simulation results are presented in this article, more you can find in corresponding references.

Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005., 2005

A challenge facing network device designers, besides increasing the speed of network gear, is improving its programmability in order to simplify the implementation of new applications (see for example, active networks, content networking, etc). This paper presents our work on designing and implementing a virtual network processor, called NetVM, which has an instruction set optimized for packet processing applications, i.e., for handling network traffic. Similarly to a Java Virtual Machine that virtualizes a CPU, a NetVM virtualizes a network processor. The NetVM is expected to provide a compatibility layer for networking tasks (e.g., packet filtering, packet counting, string matching) performed by various packet processing applications (firewalls, network monitors, intrusion detectors) so that they can be executed on any network device, ranging from expensive routers to small appliances (e.g. smart phones). Moreover, the NetVM will provide efficient mapping of the elementary functionalities used to realize the above mentioned networking tasks upon specific hardware functional units (e.g., ASICs, FPGAs, and network processing elements) included in special purpose hardware systems possibly deployed to implement network devices.

2013 Information Security for South Africa, 2013

The ability to provide the simulation of packets traversing an internet path is an integral part of providing realistic simulations for network training, and cyber defence exercises. This paper builds on previous work, and considers an in-kernel approach to solving the routing simulation problem. The inkernel approach is anticipated to allow the framework to be able to achieve throughput rates of 1GB/s or higher using commodity hardware. Processes that run outside the context of the kernel of most operating system require context switching to access hardware and kernel modules. This leads to considerable delays in the processes, such as network simulators, that frequently access hardware such as hard disk accesses and network packet handling. To mitigate this problem, as experienced with earlier implementations, this research looks towards implementing a kernel module to handle network routing and simulation within a UNIX based system. This would remove delays incurred from context switching and allows for direct access to the hardware components of the host. This implementation evaluates the use of Work Queues within the Linux Kernel to schedule packets, and Radix Trees store routing information in the form of Nodes. The memory and CPU requirements are taken into consideration, and conclusions towards the trade off of resources for higher throughput and speeds are discussed. Preliminary tests using this implementation method have achieved throughput rates in routing packets from core to endpoint host at speeds up to 1 gigabit. This however, is subject to host load, network size and number of packets being routed simultaneously at the time of transaction. These factors are discussed and suggestions made towards further optimisations.

2016

Generally, network researchers use applications that allow them to emulate or simulate networks. It is desired to obtain very close results between the ones given in a virtual and the ones obtained when the real network hardware is implemented. In this paper, we compare the experimental results obtained when a virtual network is generated by using Mininet versus a real implemented network. We have compared them varying the Maximum Transmission Unit (MTU) on Internet Protocol version 4 (IPv4) and Internet Protocol version 6 (IPv6) packets. Ethernet, Fiber Distributed Data Interface (FDDI), and Wireless Local Area Network 802.11 (WLAN 802.11) MTUs have been used in our experimental tests. KeywordsSDN; OpenFlow; Mininet; MTU; virtualization; bandwidth; jitter.

2000

Abstract Simulation is the main tool for studying networking protocols before deploying them in a wide scale, or for understanding how they are expected to behave under various conditions. IRLSim is a new packet level network simulator that we developed in the hope to study several Internet protocols.

Proceedings of the 7th Latin American Networking Conference (LANC 2012), 2012

Testing network applications and protocols in a real WAN environment can be difficult and complex due to costs and distances. Therefore, many researchers and developers use network simulation or controlled testbeds where the WAN is emulated over cheap and widely spread LAN technologies such as Ethernet. In this paper, we present an up-to-date survey of WAN emulation tools. We discuss their main characteristics and the network parameters they allow to setup and modify. We also present the results of some experiments we conducted with the tools, using both IPv4 and IPv6 traffic, in order to verify their accuracy and analyze the results obtained.

Design Automation for Embedded Systems, 2011

Network processors are special-purpose programmable units deployed in many modern high-speed network devices, which combine flexibility and high performance. However, software development for these platforms is traditionally cumbersome due both to the lack of adequate programming abstractions and to the impossibility of reusing the same software on different hardware platforms.

19th International Symposium on High Performance Computing Systems and Applications (HPCS'05), 2005

We develop a simulation model of the OSI Network Layer of packet-switching networks. We present the scope of our research and the need for simulation tools. We discuss the migration from an MS Windows interactive, real-time, GUIbased tool to two packages that can run under Linux. We describe aspects common to all serial execution versions that have been extensively used in a serial execution under the SHARCNET environment.

Protocols for High-Speed Networks V, 1997

The Network Interface Framework (NIF) is an object-oriented software architecture for providing networking services in the Choices object-oriented operating system. The NIF supports multiple dient subsystems, provides clients with low-latency noti:fication of received packets, and imposes no particular structure on clients. By contrast, traditional BSD UNIX-style networking does not meet the last tworequirements, since it forces clients to use software interrupts and queueing. BSD UNIX cannot accomodate a process-based protocol subsystem such as the z-Kernel, whereas the NIF can. We have ported the z-Kernel to Choices by embedding it into the NIF. Using the standard z-Kernel protocol stack with NIF yields Ethernet performance comparable to BSD networking. The NIF is also flexible enough to support services that cannot easily be supported by traditional BSD, such as quality-of-service for multimedia. Preliminary performance results for asynchronous transfer mode (ATM) networks show that the NIF can be used to minimize jitter for continuous media data streams in the presence of non-realtime streams.

Gesellschaft für Informatik, 2005