SIP Tools Making calls direct without Server 

1- Get Free License

2:
Inter your activation code * Free Or paid license
Click Activate

3:
Here your Internet IP address you need to add into your softswitch or GSM gateway as wholesale IP 2IP 

4:
Add user or any caller ID to test + your Sip server IP address or your GSM gateway IP address
Click access test Traffic

5:
you are ready to test call