ip firewall pptp help

Best regards to all. I need help about firewall logs. In log messages i see pptp info from some ip addresses but i do not know what they mean because no log of connection attempts or wrog user or password log. Whether someone knows something about this ?

Log messages:

Sep/14/2016 22:59:38 firewall,info pptp input: in:ether1 out:(none), src-mac “my 4g router”, proto TCP (SYN), 113.240.250.154:40298->192.168.8.2:1723, len 40
Sep/18/2016 01:31:27 firewall,info pptp input: in:ether1 out:(none), src-mac “my 4g router”, proto TCP (SYN), 80.85.84.75:57021->192.168.8.2:1723, len 40
Sep/18/2016 07:32:03 firewall,info pptp input: in:ether1 out:(none), src-mac “my 4g router”, proto TCP (SYN), 80.85.84.75:43581->192.168.8.2:1723, len 40