Soft Switching System Application Business Programming Interface Programming

The develop of Softswitch technical promoted the combination of the traditional Voice Network and IP Network, and transferred to the next generation network which based on Grouping Transmission gradually. As core of calling control, Softswitch equipment provided an opened platform for VAS, and integrated abilities of network in existence, at the same time, it can opened the core abilities and sources to the third part at the edge of network. It is possible to offer abundant VAS for user in the combinated network.This paper starts with development of telecommunication network business, imports analysis about the structure of softswitch and next generation network, then the article dicribes an opened business interface standard-Parlay/OSA which is the most representative and influential: describes the system and usage of all parts of Parlay.Combined with practice, The author choosed Appium Gbox to be the Parlay business development environment, design the calling forbidden business in softswitch, described main courses from softswitch system to Parlay gateway through SIP protocol, and the course of Parlay gateway to VAS application server through Parlay API. We can see, Parlay/API is abstract of bottom network ability, completely shields complexity of bottom network, it made top business have no association with bottom network of differ structure. Based on Parlay Gateway, the third part can implete new VAS by using API.