PSTN/ISDN emulation subsystem (NGN) (PES)

The PSTN/ISDNEmulation Subsystem( PES) is a control system in the NGN architecture, Next Generation Network.

The PES subsystem belongs to the Service Control Subsystems and provides for the emulation of analog telephone network (PSTN) and digital ISDN. This subsystem is used to connect analog and digitaltelephony to the all- IP network of the Next Generation Network (NGN).

The PES subsystem was specially developed to replace components that operate with time division multiplex(TDM), while other terminals can continue to operate unchanged.