Virtual Private Network (VPN) technology provides a way of protecting information being transmitted over the Internet, by allowing users to establish a virtual private “tunnel” to securely enter an internal network, accessing resources, data and communications via an insecure network such as the Internet. A VPN is a communications environment in which access is controlled to permit peer connections only within a defined community of interest, and is constructed though some form of partitioning of a common underlying communications medium, where this underlying communications medium provides services to the network on a nonexclusive basis. arabic 6 English 50
Mariam Abojela Msaad, Amer R. Zerek, Hana H. saleh(1-2012)

This paper describes a proposal for FAT tree based Network-on- Chip system based on MPLS forwarding mechanism. The FAT tree includes processing nodes and communication switches. IP node (processing nodes) has a message generator unit which randomly generates messages to different destinations with different packet lengths and buffering. The switch is based on MPLS technique and consists of the following units: crossbar switch, input/output link controllers and routing and arbitration units. A simulator has been developed in C++ to analyze the proposed architecture. A comparison with wormhole switch is provided to show the efficiency of the MPLS designed switch arabic 12 English 65
Azeddien M. Sllame, Nagwa Abobaker Salama(1-2016)

A denial of service attacks are usually employed to interrupt the system's activity by getting a large number of fake requests, which leads to slowing down and stopping information system or network operations. This paper outlines the basic principles of DDoS attacks, explains how DDoS attack works. The paper presents an experimental using OPNET simulation tool in which traffic from three different applications VoIP, FTP, and HTTP is used to make the practical model with a firewall shield to model and simulate DDoS over Internet. However, three scenarios have been developed to illustrate different aspects of the DDoS over networks. The results clearly demonstrate how firewalls can be configured to mitigate DDoS attacks
Azeddien M. Sllame, Reema A. Saed, Mariam Abojella Msaad(5-2021)