code: public void setTransportParam(String transport) {
  		try {
  			getSipURI().setParameter(TRANSPORT, transport);
  			super.parameters.put(TRANSPORT, transport);
  		} catch (ParseException e) {
  			logger.error("error setting transport ", e);
  		}
  	}
docs: /*
  (non-Javadoc)
  @see javax.servlet.sip.SipURI#setTransportParam(java.lang.String)