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 Add more friends to your messenger and enjoy! Go to http://messenger.yahoo.com/invite/