Today, computing networks continue to evolve, and quite rapidly. The gap between local and global networks is constantly narrowing, largely due to the emergence of high-speed territorial communication channels that are as good as the cable systems of local networks. In global networks there appear services of access to resources, as convenient and transparent as services of local networks. The most popular global network – Internet – demonstrates such examples in large numbers.

Local networks are also changing. Instead of passive cable connecting computers, they have a large number of various communication equipment – switches, routers, gateways. Thanks to such equipment it became possible to build large corporate networks with thousands of computers and a complex structure. The interest in large computers was revived, mainly because after the euphoria about the ease of working with personal computers had subsided, it turned out that systems consisting of hundreds of servers were more difficult to maintain than a few large computers. Therefore, at a new turn of the evolutionary spiral mainframes began to return to corporate computing systems, but already as full-fledged network nodes that support Ethernet or Token Ring, as well as the TCP/IP protocol stack, which became a de facto network standard thanks to the Internet.

Another very important trend has emerged, affecting both local and global networks to the same extent. They began to process information – voice, video images, drawings – that was not previously typical of computer networks. This required changes in protocols, network operating systems and communication equipment. The complexity of transmitting such multimedia information over the network is related to its sensitivity to delays in the transmission of data packets – delays usually lead to distortion of such information in the final nodes of the network. Since traditional computing network services – such as file transfer or e-mail – produce low-latency traffic and all network elements were designed with this in mind, the advent of real-time traffic has caused major problems.

Today these problems are solved in various ways, including with the help of ATM technology specially designed for the transmission of different types of traffic. However, despite the considerable efforts made in this direction, an acceptable solution to the problem is still far away, and much remains to be done in this area in order to achieve the cherished goal of merging not only the technologies of local and global networks, but also the technologies of any information networks – computing, telephone, television, etc.