SIP2.0 401 Unauthorized response when dial 7777 to Asterisk

sip 7777When I call from a GSM cell phone, my TG100 GSM gateway answers and dials extension 7777 to server, Extra 10% Off + Free Shipping on Your First App Purchase |When I call from a GSM cell phone, my TG100 GSM gateway answers and dials extension 7777 (confured as a hot on TG100) to asterisk server