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Slajd 19

Classification (functional criterion)

•    Supervisory: monitoring the status of a linę or Circuit (idle, busy)

•    Adressing: transferring routing and destination signals

•    Alerting: anouncing the incoming cali

•    Billing: generation and collection of biling information

Slajd 20

Correlation between switching and signalling technology

•    There is tight relation between main technologies used in switching and transmision equipment and signalling concepts

•    It was easier to change the signalling concept than intra-network technology

Slajd 21

• There is strong pressure to preserve usage of old technology in new changing environment - issues of interworking

Correlation between switching and signalling technology

switching technology	signalling
step-by-step	dc,
cross-bar	ac, MF, out-band
electronic	MF, out-band
SPC	message based