Hello All,
i want to make a connection between a sip soft phone and my telephony central. my central has sip client features. so how can i make a communication?
Regards…
Please clarify what you mean by “my telephony central” Are you running FreePBX? What version? Is it a Distro or installed by hand?
this is not a freepbx issue. this is general voip issue
Generally speaking you can use a VPN which is the safest way or open up your firewall to allow the appropriate traffic through, then configure the phone.
Would I be correct that you are not even running FreePBX since you refused to tell us what version you are running. 
yes i don’t use free pbx and i am a new about sip or another voip issues. so, i couldn’t explain my problem. thanks