In Figure 7, two types of
end-user devices are connected to the ISDN network:
Terminal equipment type 1 (TE1) device—Designed
to connect directly through an ISDN telephone line.
Terminal equipment type 2 (TE2) device—Not
designed for ISDN. TE2 devices—for example, analog telephones
or modems—must connect to the ISDN network through a terminal
adapter (TA).
A terminal adapter allows non-ISDN devices on the ISDN network.
