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Introduction
Published in Heqing Zhu, Data Plane Development Kit (DPDK), 2020
This is a famous and popular DPDK example, as it is frequently used to measure DPDK performance metrics. The typical test scenario, server, is installed with the high-speed Ethernet adapters and connected with PCIe slots. Ethernet ports of the server platform are connected with the external hardware packet generator (usually from IXIA or Spirent), and the l3fwd sample can demonstrate 200 Gbps forwarding rate on dual-socket server platforms easily. In this sample, the packet is received from Ethernet. CPU will check the IP header for validation, and it will complete the routing table lookup using the destination IP address. Once the destination port is found, the packet is sent out with IP header modification like TTL update. Two routing table lookup mechanisms are implemented: the exact match based on the destination IP address and the LPM-based lookup. The l3fwd sample contains more than 2,700 lines of code (including blank lines and comment lines), and the main body is actually a combination of the HelloWorld and Skeleton.
Tactile Internet over Fiber-Wireless–Enhanced LTE-A HetNets via Artificial Intelligence-Embedded Multi-Access Edge Computing
Published in Yulei Wu, Haojun Huang, Cheng-Xiang Wang, Yi Pan, 5G-Enabled Internet of Things, 2019
Amin Ebrahimzadeh, Martin Maier
Typically, haptic samples should be packetized and transmitted immediately once new sensor readings are available to help keep the end-to-end delay as small as possible. This implies a real-time transport protocol (RTP), user datagram protocol (UDP), and Internet protocol (IP) header of 12, 8, and 20 bytes, respectively [11]. For each DoF, the haptic sample of the aforementioned experimental sensor readings comprises 8 bytes. Note that NDoF haptic samples are encapsulated into one RTP/UDP/IP packet, where NDoF denotes the number of DoF in either experiment (i.e., 1 in our case). Thus, the packet size is equal to 40 + 8 NDoF bytes.
Test Bed for Evaluation of Power Grid Cyber-Infrastructure
Published in Katalin Popovici, Pieter J. Mosterman, Real-Time Simulation Technologies, 2017
David C. Bergman, David M. Nicol
No matter the actual implementation of the protocol in the simulator, the protocol must be able to handle all three layers of the stack (Data Link, Transport, and Application). Inside the simulator, we treat the three layers as a combined payload to be transported by TCP/IP, and packets are routed using the IP header as opposed to the Data Link Layer header. However, when dealing with emulated packets, the Data Link source and destination fields are used to direct packets to and from the proper hosts. More information about this can be found in Section 14.2.3, which discusses how translation is done between the IDs of the virtual hosts and their emulated DNP3 addresses.
An international value chain of China’s manufacturing industry based on big data technology
Published in Journal of Control and Decision, 2023
Liu Ning, Shen Zhifeng, Zang Jianglong, Li Xialing
A congestion header similar to that of XCP, as shown in Figure 2, is added to each packet sent. Two areas, H_cwnd and H_rtt, record the congestion window estimate and RTT, respectively. H_feedback carries the feedback information from the router and the receiver. When a packet is transmitted, the sender writes the initial RTT value , the current congestion window, and the initial feedback value in the congestion header (IP header). When an ACK is received, the sender updates the window value and recalculates the RTT value. The window value is updated based on the router feedback value to update the congestion window as shown in formula (22), where is the throughput rate of change factor, is the time to empty the queue, and the router buffer setting is and the link capacity is . The method for calculating RTT can be modelled after TCP Reno.
An Optimal Reinforced Deep Belief Network for Detection of Malicious Network Traffic
Published in IETE Journal of Research, 2023
A block of the payload for a packet, a packet header field, or a packet header byte can all be considered fields in a packet. A first trial trims a packet to n = 54 bytes, a defined length by treating a field in the packet header as a word. The word size change depending on how long the fields are in the packet. The generated sentence follows a grammar rule that is created by the packet structure’s strict adherence to the field order. The resource usage is extremely effective because the extracting field step is carried out concurrently with packet decoding or reading which is data pre-processing. As well, the packet will be padded by means of zeros if its size is less than n bytes. Because most Transmission Control Protocol (TCP) packets have a 20-byte Internet Protocol (IP) header, a 20-byte TCP header, and a 14-byte Media Access Control (MAC) header, 54 bytes are the reason to look at them.
Identification of Network Application Behaviors Hiding in HTTP Tunnels
Published in IETE Technical Review, 2021
Huiwen Bai, Guangjie Liu, Weiwei Liu, Jiangtao Zhai, Luhui Yang, Yuewei Dai
The HTTP tunneling softwares are usually based on the client/server mode. The server is in the state of waiting for requests, and the client is the sender of requests. After receiving the packet generated by native applications, the client repackages it into an HTTP message. Each new packet consists of an HTTP header in the application layer, TCP header in the transport layer, and IP header in the network layer. The destination port number of the TCP header is 80, and the destination IP address of the IP header is the public network IP of the HTTP tunnel server. There are two types of HTTP tunneling requests on the client-side: GET and POST. The request packets may contain the IP address and port number of the actual destination host in the HTTP header field. And packets with the POST method are used to send application data to the server. In theory, there's no limit to the length of the POST request message, and the maximum length of a single packet depends on Maximum Transmission Unit (MTU) of the communication interface. Therefore, tunneling packets with the POST method can carry the enormous number of uploading bytes in a flow. The size can be up to MB or even more, however, the normal POST request packets sent by the browser only upload basic form data with at most several kilobytes (KB).