PSTN Hierarchy cont.
			n Local (example, within a city) n Subscriber connections n Switching within the local exchange n Switching to other exchanges n Transit (county level, say between Tampere and Helsinki) n Switching traffic between different geographical areas within one country n International n Gateway-type traffic between n different countries n DWDM (Dense Wavelength Division Multiplexing) routes n Rates can follow SONET or SDH standard