Arul,
Yep, and as it states “DTMF tones are used during a call to signal to a far-end device for purposes of navigating a menu system, entering data, or other manipulation”, the devices to which this refers is a combination of IP phones, trunks and gateways in the system since DTMF tones have to traverse these devices to reach out for example an IVR system (they "might require MTPs" because it depends on the capabilities of the devices involved in the call). For simple communication between two IP phones it is not required since you don’t need to send DTMF tones between IP phones, or at least I cannot think of a situation in which you need to do it.
