properties.setProperty("gov.nist.javax.sip.RECEIVE_UDP_BUFFER_SIZE", "65536");
properties.setProperty("gov.nist.javax.sip.SEND_UDP_BUFFER_SIZE", "65536");
properties.setProperty("gov.nist.javax.sip.CONGESTION_CONTROL_ENABLED", "false");
try {
// Create SipStack object
sipStack = sipFactory.createSipStack(properties);
} catch (PeerUnavailableException e) {
// could not find
// gov.nist.jain.protocol.ip.sip.SipStackImpl
// in the classpath
e.printStackTrace();