Chapter 13. The Telephony Profiles

Continuing our examination of the profiles, we now visit those that are based upon telephony functions. We include here the cordless telephony, intercom and headset profiles. As described in Chapter 10, the fax and dial-up networking profiles also make some use of telephony protocols, but we consider these part of the networking group that is covered in Chapter 15. All three telephony profiles discussed here primarily address voice telephony functions. They all target telephony devices (mostly mobile phones and headsets) and thus they exist largely for use by telephones.^[1] In fact, the intercom and cordless telephony profiles instantiate two different aspects of the three-in-one phone usage scenario introduced in Chapter 3, although the cordless telephony and headset profiles explicitly address the use of computer audio in addition to telephone audio.

^[1] We suppose that other types of devices could implement these profiles. There is no reason that, say, a computer could not provide intercom profile function if it had the appropriate voice and TCS-BIN support. But in general the telephony profiles center around telephones.

These telephony profiles, then, are expected to be implemented in many mobile telephones and other telephony equipment used with phones, like headsets and voice access points. All are intended to carry voice traffic, and in fact it is this common element that caused us to group them for this chapter's discussion.^[2]

^[2] These profiles could have been referred to as "telephony audio" or "voice telephony" profiles but we opted for the briefer yet still descriptive "telephony profiles."