Analysis of the peculiarity the main concepts of construction virtual networks

Abstract

The TCP / IP stack-based communication environment does not always meet the needs of the speed of commissioning and the speed of reconfiguration of modern multiservice networks. The solution to this problem is to implement such a network architecture, in which the logic of traffic management is removed from the software of routers and switches and designed as a separate logic of centralized network management. A network built on this architecture is called Software Defined Network (SDN). Logically centralized software model does not mean physical centralization of the system. Instead, SDN workstations rely on physically distributed control levels. Sharing these levels is key to achieving the desired flexibility of the network, while separating the problem of network management into simpler tasks while simplifying the introduction of new abstractions.

The article covers the concept of software-configured networks in the context of two concepts of their construction, namely, software-defined (SDN) networks and virtualization of network functions (NVF). The NVF approach involves separating the functions of logical network elements from their hardware infrastructure by virtualizing such functions. All of this makes it possible to use unified computer hardware that delivers extensive computing capabilities to manage bandwidth. In this case, the resources of the unified equipment can be dynamically redistributed between the software implemented virtual network functions.

In terms of practical implementation, the NVF concept is more interesting now. In this model, the switches do not abstract from the performance of network management functions, but only delegate such functions to the SDN controller or to some set of virtual network services. Despite the later appearance of telecommunication services, compared to the concept of SDN, telecommunications market operators are considering the possibility of implementing NVF solutions in the short and medium term. The main reasons for this are, firstly, that the implementation of NVF can be limited and progressive through the provision of new services and without early replacement of successfully used equipment. Second, for MVF solutions, unlike SDN solutions, there is already a well-established application practice associated with cloud and other solutions that makes the NVF concept more mature and commercially available.

The main factors hampering the development of NFVs include insufficiently developed standards, leading to diversity in vendor implementations and NFV interoperability issues across vendors; organizational problems of telecommunication operators are connected with necessity of transfer of a part of functions from technical department to the department of information technology. In general, the transition to NFV can be compared to the transition from analogue telephone exchanges to digital ones in the early 1970s, when equipment manufacturers experienced the same reorientation and re-equipment.