psdn การใช้

• Whilst there are several technologies that are superficially similar to the PSDN, such as Integrated Services Digital Network ( ISDN ) and the Digital Subscriber Line ( DSL ) technologies, they are not examples of it.
• Originally the term PSDN referred only to Packet Switch Stream ( PSS ), an X . 25-based packet-switched network, mostly used to provide leased-line connections between local area networks and the Internet using permanent virtual circuits ( PVCs ).