TCP Protocol

2020 ◽  
pp. 325-335
Author(s):  
Drago Hercog
Keyword(s):  
Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1755
Author(s):  
Chanh Minh Tran ◽  
Tho Nguyen Duc ◽  
Phan Xuan Tan ◽  
Eiji Kamioka

With the introduction of HTTP/3, whose transport is no longer the traditional TCP protocol but the novel QUIC protocol, research for solutions to the unfairness of Adaptive Streaming over HTTP (HAS) has become more challenging. In other words, because of different transport layers, the HTTP/3 may not be available for some networks and the clients have to use HTTP/2 for their HAS applications instead. Therefore, the scenario in which HAS over HTTP/3 (HAS/3) competes against HTTP/2 (HAS/2) must be considered seriously. However, there has been a shortage of investigations on the performance and the origin of the unfairness in such a cross-protocol scenario in order to produce proper solutions. Therefore, this paper provides a performance evaluation and root-cause analysis of the cross-protocol unfairness between HAS/3 and HAS/2. It is concluded that, due to differences in the congestion control mechanisms of QUIC and TCP, HAS/3 clients obtain larger congestion windows, thus requesting higher video bitrates than HAS/2. As the problem lies in the transport layer, existing client-side ABR-based solutions for the unfairness from the application layer may perform suboptimally for the cross-protocol case.


2021 ◽  
Author(s):  
Vineeth S

Federated learning is a distributed learning paradigm where a centralized model is trained on data distributed over a large number of clients, each with unreliable and relatively slow network connections. The client connections typically have limited bandwidth available to them when using networks such as 2G, 3G, or WiFi. As a result, communication often becomes a bottleneck. Currently, the communication between the clients and server is mostly based on TCP protocol. In this paper, we explore using the UDP protocol for the communication between the clients and server. In particular, we develop UDP-based algorithms for gradient aggregation-based federated learning and model aggregation-based federated learning. We propose methods to construct model updates in case of packet loss with the UDP protocol. We present a scalable framework for practical federated learning. We conduct experiments over WiFi and observe that the UDP-based protocols can lead to faster convergence than the TCP-based protocol -- especially in bad networks. Code available at the repository: \url{https://github.com/vineeths96/Federated-Learning}.


2019 ◽  
Vol 2019 (6) ◽  
pp. 92-97
Author(s):  
Кирилл Батенков ◽  
Kirill Batenkov ◽  
Александр Королев ◽  
Aleksandr Korolev ◽  
Михаил Илюшин ◽  
...  

The aim of the work is to investigate statistical characteristics of multimedia services traffic of IP-network on the basis of the service information analysis of package headings. The investigation method is mathematical mod-eling in the Mathcad 14 environment. As a result of the investigations, a mathematical apparatus allowing the fulfillment of a point and interval assessment of separate constituents of voice messaging quality and also the decisionmaking regarding the satisfaction degree by users with the service offered. In the work on the basis of measurements with the aid of the Wireshark program and the TCP protocol there are carried out the investigations of permissible fields in a quality parameter variation of voice message perception. A stochastic tie is revealed between transfer standard quality parameters by means of plotting diagrams and histograms of the assessments of these parameters mutual impact. The most significant indices of transfer quality parameters form the standpoint of their impact upon quality of voice message perception are RTT indices and loss factors.


2019 ◽  
Vol 16 (2) ◽  
pp. 30
Author(s):  
Fakhrur Razi ◽  
Ipan Suandi ◽  
Fahmi Fahmi

The energy efficiency of mobile devices becomes very important, considering the development of mobile device technology starting to lead to smaller dimensions and with the higher processor speed of these mobile devices. Various studies have been conducted to grow energy-aware in hardware, middleware and application software. The step of optimizing energy consumption can be done at various layers of mobile communication network architecture. This study focuses on examining the energy consumption of mobile devices in the transport layer protocol, where the processor speed of the mobile devices used in this experiment is higher than the processor speed used in similar studies. The mobile device processor in this study has a speed of 1.5 GHz with 1 GHz RAM capacity. While in similar studies that have been carried out, mobile device processors have a speed of 369 MHz with a RAM capacity of less than 0.5 GHz. This study conducted an experiment in transmitting mobile data using TCP and UDP protocols. Because the video requires intensive delivery, so the video is the traffic that is being reviewed. Energy consumption is measured based on the amount of energy per transmission and the amount of energy per package. To complete the analysis, it can be seen the strengths and weaknesses of each protocol in the transport layer protocol, in this case the TCP and UDP protocols, also evaluated the network performance parameters such as delay and packet loss. The results showed that the UDP protocol consumes less energy and transmission delay compared to the TCP protocol. However, only about 22% of data packages can be transmitted. Therefore, the UDP protocol is only effective if the bit rate of data transmitted is close to the network speed. Conversely, despite consuming more energy and delay, the TCP protocol is able to transmit nearly 96% of data packets. On the other hand, when compared to mobile devices that have lower processor speeds, the mobile devices in this study consume more energy to transmit video data. However, transmission delay and packet loss can be suppressed. Thus, mobile devices that have higher processor speeds are able to optimize the energy consumed to improve transmission quality.Key words: energy consumption, processor, delay, packet loss, transport layer protocol


2020 ◽  
Vol 8 (4) ◽  
pp. 475
Author(s):  
Maria Okta Safira ◽  
I Komang Ari Mogi

In this paper two methods are used, namely the vigenere cipher method and the RSA method. The vigenere cipher method is an example of a symmetric algorithm, while RSA is an example of an asymmetric algorithm. The combination of these two methods is called hybrid cryptography which has the advantage in terms of speed during the encryption process. Each process, which is encryption and decryption, is carried out twice, so that security can be ensured. In the process of forming the key used the RSA method. In the encryption process using public keys that have been generated before when the key is formed. This public key is used in sending data to the recipient of a secret message where this key is used for the data encryption process. The Secret key is kept and will be used during the decryption process. There is a system architecture that describes how clients and servers communicate with each other over the internet using the TCP protocol where the client here is an IoT device and the server is a server. 


Author(s):  
Xushi Mei ◽  
Xiaolong Chen

When a source end adopted FAST TCP to actively control the sending window, and the link end adopted active queue management algorithm, if the network parameters were improperly set, the system can be unstable. The relationship between the stability and network parameters was quantitatively analyzed. Aiming at the defect of network instability caused by radical window halving strategy, a new method based on stability analysis was proposed to make full use of the historical change information obtained by the source-end and to improve the window adjusting strategy of FAST TCP protocol according to the congestion status. Thus, the parameters of the active queue controller was modified indirectly to improve the stability of the system. Ns-2 simulation result verified the accuracy of the stability theory analysis and the effectiveness of the improvement strategy.


Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3880
Author(s):  
Dmitri Moltchanov ◽  
Aleksandr Ometov ◽  
Pavel Kustarev ◽  
Oleg Evsutin ◽  
Jiri Hosek ◽  
...  

Dynamic blockage of radio propagation paths between the user equipment (UE) and the 5G New Radio (NR) Base Station (BS) induces abrupt rate fluctuations that may lead to sub-optimal performance of the Transmission Control Protocol (TCP) protocol. In this work, we characterize the effects of dynamic human blockage on TCP throughput at the 5G NR air interface. To this aim, we develop an analytical model that expresses the TCP throughput as a function of the round-trip time (RTT), environmental, and radio system parameters. Our results indicate that the blockage affects TCP throughput only when the RTT is comparable to the blocked and non-blocked state durations when the frequency of state changes is high. However, such conditions are not typical for dynamic body blockage environments allowing TCP to benefit from the high bandwidth of 5G NR systems fully.


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