The VoIP gateway can perform the digitization, () and encapsulation required, and it controls the setup of VoIP calls between the calling device and the called device
A Next Generation Network(NGN) is a () network ,which is able to provide Telecomunication Services ti users and to make use of multiple broadband, QoS-enable transport technologies and in which service-related functions are (下题选择) of the underlying transport-related technologies.