Most local ISPs (Internet Service Provider) will provide name server for internet connections. Application will query name server by using APIs provided by operation systems, for example Windows or Linux. By default, these APIs are synchronous. It works well in most scenarios. But if there are some problems in name servers, applications will be blocked by these DNS APIs. For VoIP server, such as miniSIPServer, it will have to stop work to wait DNS result and discard all calls.
To resolve this problem, we need
miniSIPServer V22 or abover has its own asynchronous DNS procedures, and the default DNS server is Google DNS system.
You need do nothing by default.
If you want to replace Google DNS servers with your own DNS servers, you can configure "gVarSysMDNS" and "gVarSysSDNS" in "mss_var_param.ini" file to indicate your master DNS server and slave DNS server.
Here is an example.
[sys] gVarSysMDNS=22.214.171.124 gVarSysSDNS=126.96.36.199
Please pay attention that you need restart miniSIPServer if you change above parameters.