Hi, We encountered a critical clock_thread() stuck/blocked issue, the render was starving and the call was not able to reset. Moreover, It prevent the pjsip stack from quitting. This issue was caused by receiving illegal/malformed RTP packages, which triggered a pjmedia_clock_modify() and got a massive clock interval. clock_thread() hence fell into a deep sleep. pjmedia_clock_modify() should validate the result calculated from the RTP param and ignore the values more than max_jump. -- Deng Xiaoming dengxiaoming@gmail.com