secure maintenance link

Similar to a secure association, but, it differs in the following ways: a) used to send a command from the FSU to an endpoint; b) the FSU cannot issue a command to an endpoint not in the immediate vicinity (for instance, an FSU in Sacramento cannot send a command to an endpoint in Bakersfield); c) a secure maintenance link expires in one hour unless the FSU is idle, in which case, it expires in five minutes; d) they use RSA keys, not Elliptical Curve (EC) keys, for authentication. See also secure association (SA).