Including both dedicated installations and those operating as outsourced communications services but always focusing on the fact that they are the means of transporting data from one place to another.

    [PSTN] telephone network

    [ISDN] digital network

    [X25] data network

    [ADSL] ADSL

    [pp] point to point

    [radio] wireless network

    [sat] satellite

    [LAN] local network

    [MAN] metropolitan network

    [Internet] Internet

    [vpn] virtual private network