In this section you have learned that:

• ISDN equipment is called Terminal Equipment
• There are two classes of TE:  TE1 and TE2.
• TE1 is ISDN aware equipment (e.g. an ISDN telephone)
• TE2 equipment is not ISDN aware (e.g. an analogue telephone)
• A Terminal Adapter is the equipment required to connect TE2's to an ISDN network
• An NT1 is the termination of the network
• Reference Point S/T is on the user side of the NT1
• Reference Point U is the network side of the NT1
• In EuroISDN, the user connects to Reference Point S/T and the network provider supplies the NT1
• In North America, the user connects to Reference Point U and has to provide the NT1