On limits of embedded systems in network packet processing

The paper deals with a measurement of single-hop one way packet delay on embedded systems used for networking. The single-hop one way packet delay is essential parameter when we need to process packets with strict delivery time constrains. Comparison of different approaches to single-hop one way packet delay measurements is presented in this work along with discussion about strong and weak points in specific measurement approach. The impact of different types of system load and number of CPU cores are also covered by presented results. The presented results of measurement single-hop one way packet delay in embedded Linux system show that for the specific system configuration the packet processing delay depends (in different ways) on system load and network stack load

CER/TER - the new metric for TCP connection robustness evaluation and comparison

This article presents new metric for TCP connection robustness evaluation and comparison. This metric is focused on TCP connection and transmission continuity rather then on maximal throughput or minimal RTT. This metric is developed especially for evaluation of narrow band networks. That is why it is very convenient to use this metric for networks such as Internet of Things networks or industrial sensor networks. Our metric is based on observing if connections or transmissions are successfully finished or not. It is possible to optimize this metric for specific situations. This metric can be used in both the real networks and in discrete simulation environments

FlowPing - the new tool for throughput and stress testing

This article presents a new tool for network throughput and stress testing. The FlowPing tool is easy to use, and its basic output is very similar to standard Linux ping application. The FlowPing tool is not limited to reach-ability or round trip time testing but is capable of complex UDP based throughput stress testing with rich reporting capabilities on client and server sides. Our new tool implements features, which allow the user to perform tests with variable packet size and traffic rate. All these features can be used in one single test run. This allows the user to use and develop new methodologies for network throughput and stress testing. With the FlowPing tool, it is easy to perform the test with the slowly increasing the amount of network traffic and monitor the behavior of network when the congestion occurs

Multipath TCP in LTE networks

The results of experiments with Multipath TCP (Multipath Transmission Control Protocol) in LTE (3GPP Long Term Evolution) networks are presented. Our results show increased resiliency and availability of network Multipath TCP connection. Using multiple sub-flows over diverse network paths inside Multipath TCP session results in greatly increased bandwidth and availability. When Multipath TCP is used the behavior of this protocol is consistent in situation of adding new sub-flow or removing flow on a faulty line. Different strategies for path selection are possible with great impact on Multipath TCP session performance. Network structure consisting of few connections with similar parameters is optimal for full mesh Multipath TCP path topology. In this case the behavior of Multipath TCP predictable

Adaptable system increasing the transmission speed and reliability in packet network by optimizing delay

There is a great diversity in the transmission technologies in current data networks. Individual technologies are in most cases incompatible at physical and partially also at the link layer of the reference ISO/OSI model. Network compatibility, as the ability to transmit data, is realizable through the third layer, which is able to guarantee the operation of the different devices across their technological differences. The proposed inverse packet multiplexer addresses increase of the speed and reliability of packet transmission to the third layer, and at the same time it increases the stability of the data communication by the regulation of the delay value during the transmission. This article presents implementation of a communication system and its verification in real conditions. The conclusion compares the strengths and weaknesses of the proposed control system

Transmission Optimization Metrics Setup Issues in the Field of Time Constrained Communications

This article introduces a new approach in the field of network optimization based on Transmission Optimization Metric (TOM), which is aimed at improving traffic flow continuity and increasing the chances for traffic flow sustainability in a way that helps to minimize inter-packet gaps. The work is mainly focused on harsh transmission conditions in narrow-band networks. Finally, the presented approach has impact on better resource allocation as fewer attempts are necessary for successful completion of a transmission. A significant part of the article deals with parameterization of coefficients used by the TOM optimization method. Examples of analysis for several topologies of narrow-band wireless networks based on CSMA/CA and TDMA protocols are used to demonstrate various issues related to proper setting of parameters. The introduced TOM metric has the potential to become a standard for optimization, for example, in sensor networks that are characterized by the specific nature of data traffic

Simulation of the application layer in narrowband networks with conditional data injection XML scheme based on universal data generator

In this article, we would like to deal with challenges and analysis approaches in the area of narrow band communication networks. Especially those networks which use TCP/IP protocol family. We also present a new universal data generator for OMNeT++ simulation environment. We created this generator to satisfy the evaluation, stress testing and benchmarking demands of more and more complex industrial and the Internet of Things networks. We also present the methods for evaluation and comparison of results obtained from simulated and real TCP/IP based networks in this article