The SIP voice gateway used aluminum casting, high mechanical strength and strong impact resistance.
Support SIP application, including before the call (unconditional transfer/no answer transfer/user busy transfer), call waiting, call a hotline number, call transfer (blind turn/ask), after three calls, call hold, quickly abbreviated dial, number replace rules, restrictions, call, don’t disturb, caller id, outside threats ringing, outside threats ring and so on.
Weather can play a significant role in disrupting communication systems, especially in outdoor environments. However, the development of the English...