Maintenance activities conducted by individuals communicating external to an information system security perimeter.
Sources:
NIST SP 800-18 Rev. 1
under Remote Maintenance
Maintenance activities conducted by individuals communicating through an external network.
Sources:
NIST SP 800-53 Rev. 5
NIST SP 800-82r3
from
NIST SP 800-53 Rev. 5
Maintenance activities conducted by individuals communicating through an external network (e.g., the Internet).
Sources:
NIST SP 800-171 Rev. 2