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Review of Layer 2 and Layer 3 Forwarding
Published in James Aweya, Designing Switch/Routers, 2023
This chapter discusses the basics of Layer 2 and Layer 3 forwarding, as well as the methods a switch/router uses to decide which mode of forwarding to use (Layer 2 or Layer 3) when it receives a packet. The discussion covers the forwarding of packets within and between IP subnets, control plane and data plane separation in routing devices, the basics of routing table structure and construction, and the packet forwarding processes in routing devices. The discussion includes the key actions involved in packet forwarding. The IP packet forwarding processes involve parsing the packet’s IP destination address, performing a lookup in the IP forwarding table, and sending the packet out the correct outbound interface. This discussion helps in understanding the Layer 2 and Layer 3 processing that takes place in switch/routers. The discussion also helps in understanding the differences between the Layer 2 and Layer 3 processing that takes place in switch/routers.
Performance and evaluation of firewalls and security
Published in Sabyasachi Pramanik, Anand Sharma, Surbhi Bhatia, Dac-Nhuong Le, An Interdisciplinary Approach to Modern Network Security, 2022
Sneha Chowdary Kantheti, Ravi Manne
A firewall is a group of systems like a router, a proxy or a getaway, that is designed to permit or deny traffic or transmission of data based on security rules and regulations, and to enforce protection between two networks or to protect the inside network from the outside network. A packet is a unit that holds information and is routed from one point to another over the internet or any other network. A packet header will contain information about the size, source, destination, and origin address. A firewall, which is a filtering device, watches the packet header, packet payload or both, and it can also focus on the content of the session. Most of the firewalls will only focus on one of these. Most common filtering will focus on the header of the payload, with the payload of a packet a close second. Firewalls do the filtering, and allowing only what is wanted on the network and rejecting the other requests. There is this philosophy of security to deny by default or allow by exception, and firewalls follow this rule. Firewalls, when filtering, compare each packet received to a set of rules that were configured by an administrator. If the packet matches all the allow rules, then it will be allowed, and if the packet matches any of the deny rules, the packet will be dropped. If the content of a packet does not match with any rule, by default it will be dropped. Authorized traffic (requests) is allowed to pass through the firewall, and unwanted or unauthorized traffic is blocked.
7 Ip Packet Transport
Published in Wes Simpson, Video Over IP, 2013
Packet filtering involves looking at the source and destination IP addresses of each packet as well as the source and destination TCP and UDP ports in each packet. This inspection is generally direction sensitive, where internal users are allowed to perform one set of functions and external users are allowed to perform another. For example, consider TCP port 80, which is used by Hypertext Transfer Protocol (HTTP) on the World Wide Web (www). Anytime a user types “ http://www.xxx.com” on his or her web browser, a packet is sent to port 80 on the “xxx” server (see Figure 7-7). This packet will also include a port number on the user's PC for the reply from the website to come back to, in our example 2560. Once a connection is established, every packet between the user and the server will contain the user's IP address and port number (2560) as well as the server's IP address and port number (80). The firewall can block packets addressed to other ports on the user's machine, and it can also block packets from sources other than “xxx.com.”
Vertical handover in heterogeneous networks using WDWWO algorithm with NN
Published in International Journal of Electronics, 2021
M Naresh, D Venkat Reddy, K Ramalinga Reddy
Resultant graph 9(a) shows the PDR range vs packets per second. A number of packets increases, the PDR range will be decreasing, and data traffic also increases. At 10packets per second, the generation of PDR is 99.5% and reduces the number of packets PDR range is 97%, 95%, 93% and 92% as 20, 30, 40 and 50packets/sec. When compared with existing methods, PDR is 87%, 78% and 75% of D-TOPSIS, FIS-ENN, and F-AHP respectively at 50 packets/sec. Packet loss occurs when one or more data packets travelling over a network fail to reach their destination. Packet loss is affected by errors in the transmission of data. (Figure 9(b)) displays the packet loss. At 10, 20, 30, 40, and 50 packets/sec, ODRN shows the packet loss of 2%, 7%, 11%, 15% and 19% respectively. It is better than the existing methods of D-TOPSIS (24%), FIS-ENN (32%) and F-AHP (37%) for 50 packets/sec.
Integration of sparse singular vector decomposition and statistical process control for traffic monitoring and quality of service improvement in mission-critical communication networks
Published in IISE Transactions, 2018
QoS assurance starts from monitoring and change/anomaly detection of network traffic data. This has been primary studied by the research community of communication networks in Electrical and Computer Engineering (ECE). A typical form of network traffic data is as “packets.” A packet is a unit of data that is routed from a sender to a receiver in a network. A packet is typically structured to include a header and contents. The header includes meta-information about the packet, such as sender and receiver IP addresses and protocol. Contents are the actual data such as text, audio, and video. The header of a packet is very small in size, whereas contents can be large. The existing research falls into three major categories: Deep Packet Inspection (DPI) (Roesch, 1999; Yu et al., 2006; Smith et al., 2008; Cascarano et al., 2011), Active Monitoring (AM) (Paxson et al., 1998; Almes et al., 1999a, 1999b; Caceres et al., 1999; Ciavattone et al., 2003), and Passive Monitoring (PM) (Conway, 2002; Fraleigh et al., 2003; Ahmed et al., 2005).
Proactive flow control using adaptive beam forming for smart intra-layer data communication in wireless network on chip
Published in Automatika, 2023
Dinesh Kumar T.R., Karthikeyan A.
The value 1 is assigned to node status with H, and 0 is allocated to node_status with L. At any given time, the node status value specifies whether a data flow session can be accepted or rejected. Figure 4 shows the triangle membership function for the queue load parameter, which represents the range of membership degree (b). Let's say the LP threshold is 75 percent and the HP level is 70 percent. The queue load percent will then be assigned a membership value in each set between 0 and 1 by mapping the current queue load onto the graph of the membership function. If the current QL percent is 65, for example, the degree of membership is between 0.3 and 0.8. As illustrated in Figure 4, the value can be fuzzified into LP with a degree of 0.3 and HP with a degree of 0.8. (b). The node status is one of the major factors considered by the proposed model when making decisions during data flow control. Each node's IHAnode_status serves as a direct link for determining resource availability. It guarantees that transmitting and receiving packets are coordinated to ensure that packets are delivered correctly and on time. Because the positions of the controller (IHA node) and the destination (core) are known and static, the beam formation enforced by the controller in the proposed model steers the beam as close to the target as possible. The controller provides non-overlapping spatial channels by reconfiguring the beams every R cycle, based on previous communication requests. The phase shifters are controlled by a beam table kept by the controller. The beam table stores information about the beam direction and phase shift vector pairs. The beam direction is calculated by comparing the direction with the position of the destination core. Because the number of beam directions is small, the IHA keeps a tiny beam table, making phase shifters straightforward. The beam radiated in the direction of the destination core is depicted in Figure 5. Beam forming minimizes the strength received in interference signal directions, resulting in nulls in the radiation pattern. It can electronically and digitally change and direct the radiation pattern of an antenna array, as well as adapt it to the environment, to improve performance and efficiency.