Dear Sir

 I am new to SER .

 So I want to know , is Opensips is Open source?. Does it need license?..

 What operating system needed to install the SER.

 Does SER support totally telephony, pc-pc , pc-phone, calling card , call back , IPPBX etc..

 How many systems needed to install to work the complete solution.

 If possible , you can give me the installation and configuration ducumentation so that I can try to do the complete solution.
 
Waiting for your reply.
 
Thanks and Regards
 
Parikhita