Make and answer phone calls Detect tone and pulse digit from the phone line Capture Caller ID Support blind transfer, single-step transfer/conference, consultation transfer/conference, hold, unhold. Control of the local phone handset

语音卡呼叫系统，实现电话会议的功能，运用三方通话的原理-Voice card calling system to achieve the function of the conference call, using the principle of three-way calling