public void start(final Session session) throws OpenShiftSSHOperationException {
		if (localAddress == null || localAddress.isEmpty()) {
			throw new IllegalArgumentException("Cannot enable port-forwarding from an undefined local address");
		}
		if (localPort == -1 ) {
			throw new IllegalArgumentException("Cannot enable port-forwarding from an undefined local port");
		}
		// don't start it twice
		if (!isStarted(session)) {
			try {
				session.setPortForwardingL(localAddress, this.localPort, this.remoteAddress, this.remotePort);
			} catch (Exception e) {
				throw new OpenShiftSSHOperationException(e, "Failed to start port forwarding on {0}:{1}",
						this.localAddress, this.localPort);
			}
		}
	}