code: private void linkUp(Mtp2 link) {
  
          if (link.mtp2Listener != null) {
              link.mtp2Listener.linkUp();
          }
  
          linkset.add(link);
          if (linkset.isActive() && this.mtp3Listener != null) {
              try {
                  mtp3Listener.linkUp();
              } catch (Exception e) {
                  e.printStackTrace();
              }
          }
          if (logger.isInfoEnabled()) {
              logger.info(String.format("(%s) Link now IN_SERVICE", link.getName()));
          }
      }
docs: Notify that link is up.
  
  @param link