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I.4.1 Examples for speech and 3.1 kHz audio bearer services

a) Type II information (common):

- information transfer capability =speech or 3.1 kHz audio;

- information transfer mode = circuit;

- information transfer rate = 64kbit/s;

- user information layer 1 protocol =A/m-law.

b) Type III information for interworking with PSTN - Voice band data applications - Modem type conversion occurs - Figure I.11:

- user information layer 1 protocol =rate adaption + user rate + other attributes (if required).

Figure I.11/Q.931 – BC = 3.1 kHz audio – Voice band data –> PSTN