Aastra 6725 ip External to Lync 2013 - internal works

Hi

Phone Works internal but external do not Work. Trace debug show DHCP Inform 255.255.255.255 and nothing else. I have got diagram over request how phone communicate, but it do not help me.

I cannot get it right

Public DNS SRV and A record to FE or EDGE and Ports. I use multi domain and where to put Multi domain SSL into(FE or EDGE).

I have read everyting but nothing helps.

Please help me and write step by step what to do and where, ports, SRV and so on.

Thanks