SC-7.4: External Telecommunications Services

Statement

• (a)

  Implement a managed interface for each external telecommunication service;

• (b)

  Establish a traffic flow policy for each managed interface;

• (c)

  Protect the confidentiality and integrity of the information being transmitted across each interface;

• (d)

  Document each exception to the traffic flow policy with a supporting mission or business need and duration of that need;

• (e)

  Review exceptions to the traffic flow policy frequency and remove exceptions that are no longer supported by an explicit mission or business need;

• (f)

  Prevent unauthorized exchange of control plane traffic with external networks;

• (g)

  Publish information to enable remote networks to detect unauthorized control plane traffic from internal networks; and

• (h)

  Filter unauthorized control plane traffic from external networks.