1, basic concepts
What is the soft switching ? In asking such questions, we often get a series of features description: it is, it is the core of NGN open framework, and it can realize call control and media transport separation...
The soft switching concept originating in the United States. When in enterprise network environment, users adopt ethernet-based phone, by a set of based on PC Server Call control software (Call Manager, Call Server), realize to PBX (Branch eXchange, user level switches) function (IP PBX). For such a set of equipment, the system does not need to separate networks, but only through laying with LAN sharing can achieve management and maintenance unification, comprehensive cost far less than the traditional PBX. Because enterprise nets environment on equipment reliability, billing and management demand is not high, mainly used for satisfying the communication demand, equipment threshold low, many equipment shangdu can provide such solutions, thereby IP PBX application has achieved great success. Inspired by IP PBX success, in order to improve comprehensive network operation efficiency, the development of the network more more reasonable, open, better service for users. Industry puts forward a kind of such thoughts: will the traditional exchange equipment components, divided into call control and media processing, using standard agreement between H248) and (MGCP, mainly using a pure software processing, hence, Soft Switch (the soft switching technology arises at the historic moment.
Once the soft switching concept put forward and soon got the wide recognition of the industry concerned, and Soft Switch ISC (International Consortium) was established in the soft switching technology more quickened the pace of development of relevant standards and, the soft switching agreement got IETF, ITU - T International organization for standardization of such attention.
According to the definition of Soft Switch BBS, Soft Switch ISC is based on group nets use SPC software to provide call control function and media processing phase separation equipment and systems. Therefore, the basic meaning of the soft switching is to call control functions from the media gateway (transport layer) spinoff, through the software to realize basic call control functions, thus realize calls the separation of transmission and call control, for control, exchange and software programmable functions establish separate plane. The soft switching mainly provide connection control, translation and choose road, gateway management, call control, bandwidth management, signaling, safety and call detail records, and other functions. Meanwhile, the soft switching will also network resources and network capacity, enveloped by standard open business interface and business application layer is linked together, can easily provide fast on the network new business.
Cisco systems Asia Pacific NGN/VoIP chief technical adviser YanKang argues that, though "the soft switching " is the NGN debated, but people on its concept still some specious. He said: "' the soft switching 'Soft switch from the term can say Soft switch translation. The term borrowed from the traditional telecom domain the' hard 'processed net switch' concept 'switches, what is different based on group to emphasize its online call control and media transmission bearing the meaning of separation.
The soft switching is an evolving concept, contain many functions. Its core is a using standardized agreement and the application programming interface (API) open system structure. This is the third party to develop new applications and new business opened the door. The soft switching system structure of other important features include application of separation (DE - coupling is a marketing method), call control and load control.
2, the soft switching system thought vindictiveness
The soft switching technology distinguishes other technology, but also the most remarkable feature of the core idea of three basic elements are:
2.1, open business generated interface
The soft switching to offer business mainly via API and "way is to provide application server" matching networks business new synthesis. Meanwhile, IN order to better juggle existing communication network, it also can pass IN INAP and already available IN the SCP cooperate with offering traditional intelligence business.
2.2, comprehensive equipment access ability
The soft switching can support many of the agreement, so that to various access equipment control, utmost ground protects user investment and give full play to the role of existing communication network.
Based on the running 2.3, strategy support systems
The soft switching adopted a and traditional OAM system completely different, based on strategy (Policy - based) ways to complete the realization of the function, operation support system according to certain strategies on the network characteristics, intelligence, centralized real-time adjustment and intervention, to ensure the stability and reliability of the whole system.
As packet-switched network and traditional PSTN network fusing new solutions, the soft switching will PSTN reliability and flexibility of data networks combined well up, is emerging operators to enter the new technology voice market, but also the traditional voice network to voice the way the group. At present the soft switching in the world, as the next generation network (NGN) core components, has been more and more accepted by the operators and adoption.
No comments:
Post a Comment