Virtual Data Networks

The telecommunication domain is promoting many organizations to need to use between the long-distance place establishing the virtual data network the technology, these technologies mainly use in the campus environment, the urban region, the macrozonality, or the global region. The virtual data network all place all systems carried on the entire interconnection for the organization to provide compared to having rented the owner-use circuit and the establishment private network expense low many ways. Its goal is provides local area network's speed on WAN. 　　The packet switching service, for example the frame relay and the exchange type many megabit digital data services (SMDS, is providing the virtual data networking capability and to owner-use circuit's replacement demand. These services provide have the microsecond exchange capacity band width. The customer only need use for them serves carries on the payment. These services by long-distance telecommunication bureau, for example AT& T, MCI, and USSprint, as well as value-added network (VAC), for example CompuServe, Infonet and Tymenet and so on provide. Circuit switching service, for example exchange - 56, exchange - 384K (AT& T), exchanges T1 and exchanges T3, now with these telecommunication services equally also very popular use few expenses, now some very small place may also include in a very big business data network. 　　Moreover, individual demand is not now high, this is because these telecommunication services have processed the exchange element. Through the packet switching service, sole “the data pipeline” transmits the data from the customer place to the telecommunication bureau, then transmits again from this telecommunication bureau to other places. However, the network management personnel considered when entrusts with many network managements a public telecommunication bureau produces loses the control the question, although these telecommunication bureaus can also provide about these service suitable management information.