hi Guys, I need an urgent help, all of a sudden my sip trunks have started registering it self and then failing it self. It has started from last month and now keeps on bugging every once a week. Few days works fine and then again starts giving registration fail DNS/Network Failure issue. I have reported My ISP: Response no issue Reported Fonet: Response no issue Returning Error: Event source: 3CXPhoneSystem Registration at 7734 **** has failed. Destination (sip:*****@gw1.fonet.dk:5060) is not reachable, DNS error resolving FQDN, or service is not available. If i register the same account directly on IP Phone, it gives no error at all, which gives me a conclusion there is nothing wrong with router settings neither the ISP, account registration fails only from 3CX Management Console. Please help on it. Regards, Adnan.