Section: 5.3.6.2.2.1 Fallback to speech
Content: If modem handshaking fails (in a modem call), the call mode will be modified to speech if a speech bearer capability IE was included. The modem signalling is inband, so the call must have reached the active state, when these conclusions about the presence of modems can be done. The call modifications are realized through the in-call modification procedure, by which the network requests the MS to modify the call mode (see subclause 5.3.4.3). NOTE: Fallback from digital (UDI) H.324-call to speech after call setup is not a valid case at the terminating side.