Hello Sir/Madam, We,the students of final year Btech(IT) from India,are doing the same project in Sip VoIP.And also we are getting the same error as: gov.nist.javax.sip.SipStackImpl cannot be instantiated.Ensure the path name has been set. javax.sip.PeerUnavailableException. If you get any answer regarding this error,kindly provide us with the details immediately.We need it urgently. Bye, R.vivek & batch "work work and work that will not let u down any day,any way." "dont be happy that u re handsom.be happy that u r confident and hardworking. --------------------------------- Celebrate Yahoo!'s 10th Birthday! Yahoo! Netrospective: 100 Moments of the Web