Packet Service Profiles (PSP) specify audio encoding methods and associated media attributes that the SBC uses when negotiating the media capabilities for calls during initial call setup.
During call setup several PSP are merged to determine the encoding for the call. For a detailed description of the PSP merge process, see SBC Core Features Guide as well as "PSX Product Description" and "PSX Provisioning Guide" documents.
Four different groups of available codec and other media preferences (packet size, DTMF transport method, etc.) are available on each call:
Numerous outcomes are possible regarding which codec(s) is/are used for the call, depending on how the PSP are configured. You could, for example: