sipFactory = SipFactory.getInstance();
sipFactory.setPathName("gov.nist");
sipStack = sipFactory.createSipStack(properties);
headerFactory = sipFactory.createHeaderFactory();
addressFactory = sipFactory.createAddressFactory();
messageFactory = sipFactory.createMessageFactory();
ListeningPoint lp = sipStack.createListeningPoint(myHost, myPort, ListeningPoint.UDP);
sipProvider = sipStack.createSipProvider(lp);
sipProvider.addSipListener(this);