wn vote favorite <https://stackoverflow.com/questions/50604849/pjsua-error-error-address-already-in-use#> Hello, I am trying to make calls using PJSIP module in python. For setup of SIP transport, I am doing like trans_cfg = pj.TransportConfig()# port for VoIP communication trans_cfg.port = 5060# local system address trans_cfg.bound_addr = inputs.client_addr transport = lib.create_transport(pj.TransportType.UDP,trans_cfg) when I finish the call I am clearing the transport setup as, transport = None. I am able to make call to user by running my program. But every time I restart my PC alone, I get an error while I run my python program File "pjsuatrail_all.py", line 225, in <module> main()File "pjsuatrail_all.py", line 169, in main transport = transport_setup()File "pjsuatrail_all.py", line 54, in transport_setup transport = lib.create_transport(pj.TransportType.UDP,trans_cfg)File "/usr/local/lib/python2.7/dist-packages/pjsua.py", line 2304, in create_transport self._err_check("create_transport()", self, err)File "/usr/local/lib/python2.7/dist-packages/pjsua.py", line 2723, in _err_check raise Error(op_name, obj, err_code, err_msg) pjsua.Error: Object: Lib, operation=create_transport(), error=Address already in useException AttributeError: "'NoneType' object has no attribute 'destroy'" in <bound method Lib.__del__ of <pjsua.Lib instance at 0x7f8a4bbb6170>> ignored For this currently I am doing like $sudo lsof -t -i:5060>> 1137 $sudo kill 1137 Then I run my code it works fine. By instance from error, I can understand that somewhere I am not closing my transport configuration properly. Can anyone help in this regards. Thanks, *RAADy *