The LINEDIGITMODE_ constants describe different types of inband digit generation.
No extensibility. All 32 bits are reserved.
A digit mode can be specified when generating or detecting digits. Note that pulse digits are generated by making and breaking the local loop circuit. These pulses are absorbed by the switch. The remote end merely observes this as a series of inband audio clicks. Detecting digits sent as pulses must therefore be able to detect these sequences of 1 to 10 audible clicks.