This object specifies the line signaling type that will be used for the R2 line signaling. . digital (1): The digital line signaling is typically used for PCM systems. Only A and B bits are used to indicate line signaling states, while C and D bits may be optionally used. . analog (2): The analog line signaling is typically used for carrier systems. Only A bit is used to represent tone-on and tone-off indication to signal the line signaling states, while the B, C, and D bit are fixed. . pulse (3): The Pulse type line signaling is typically used for satellite links. It uses tones sent as pulses to indicate line signaling states.