I have a zabbix proxy configured in active mode which send data to remote Zabbix server. However sometimes Zabbix is not able to send data to Zabbix server and in the log file i get the following message

cannot send proxy data to server at "zabbix.server.hostname": ZBX_TCP_READ() timed out

This happens intermittently, I have tried using TCP dump and have found some re transmission TCP packets during the same time. I would like to know what best i can do to further troubleshoot this issue

Is TCP re transmission due to some network issues because when i telnet to or from server it works fine.