code: public String getInitialTransport() {
  		if(getTransaction() != null) {
  			return ((SIPTransaction)getTransaction()).getTransport();
  		} else {
  			ViaHeader via = (ViaHeader) message.getHeader(ViaHeader.NAME);
  			if(via == null ||
  					// https://github.com/Mobicents/sip-servlets/issues/47
  					// check if the via is container generated, if it is then it means
  					// this is an outgoing request or response and thus should return null
  					!sipFactoryImpl.getSipApplicationDispatcher().isViaHeaderExternal(via) ) {
  				return null;
  			} else {
  				return via.getTransport();
  			}
  		}
  	}
docs: {@inheritDoc}