Network Security (Security)
There are two types of security tools for computer networks:
• Means of protecting internal information resources. These tools should protect hardware resources (servers, disk arrays, routers), software resources (operating systems, database management systems, mail services) and data stored in files and processed in RAM from unauthorized access. Such a tool is the firewall (Firewall), installed in the locations of all internal network connections with the external (Internet). The firewall controls the exchange of data and does not allow the transmission of suspicious traffic to the internal network;
• means of protecting information in the process of its transmission through the network. These include virtual private networks.
Indicators for the service provider
These, most often qualitative, indicators are used to assess the effectiveness of the network.
Expandability of the network (Expansibility) - the ability to expand functionality, add users, computers, applications, services, increase the length of cable segments and replace the existing hardware with more powerful.
Network Scalability (Scalability) - the ability to increase the number of devices, nodes, and the length of network connections without reducing its performance. An example of a well-scaled network is the Internet.
Network Manageability (Controllability). Controllability means the possibility of centralized control over the state of network equipment, the identification and resolution of emerging problems, performance analysis and network development planning, and the availability of automated administrative tools in the network that interact with the software and hardware of the network using communication protocols.
Compatibility (integrability ) networks, which means the ability of a network to include a wide variety of software and hardware supporting different communication protocol stacks, hardware and applications. A network consisting of heterogeneous elements is called heterogeneous, or heterogeneous. The main way of building integrated networks is the use of modules executed in accordance with open standards and specifications.
About Quality of Service
The use of the packet switching principle in computer and other telecommunication networks made the Quality of Service (QoS) problem a topical issue. The essence of it is that the switching principle requires a buffer memory to store the packets in order to avoid their loss. Packet buffering is the main mechanism for maintaining high performance and serves as protection against network congestion when transmitting a pulsating data stream (traffic). However, buffering creates queues that cause an undefined packet delay, which is highly undesirable for delay-sensitive traffic (sound, video). QoS quality assurance methods minimize delays for such traffic and guarantee an average transmission rate for elastic data traffic. Without their application, the work of such modern multimedia applications as IP-telephony, video and broadcasting is impossible. Currently, a large number of different methods and algorithms have been developed (priority and weighted queues, redundancy, bucket bucket algorithms, etc.) that provide quality of service for delays sensitive and elastic traffic. Methods of providing quality of service adjoin the methods of traffic engineering, which consist in choosing rational routes for passing traffic through the network.