NIST 800-53 REV 5 • PHYSICAL AND ENVIRONMENTAL PROTECTION
PE-4 — Access Control for Transmission
Control physical access to {{ insert: param, pe-04_odp.01 }} within organizational facilities using {{ insert: param, pe-04_odp.02 }}.
Supplemental Guidance
Security controls applied to system distribution and transmission lines prevent accidental damage, disruption, and physical tampering. Such controls may also be necessary to prevent eavesdropping or modification of unencrypted transmissions. Security controls used to control physical access to system distribution and transmission lines include disconnected or locked spare jacks, locked wiring closets, protection of cabling by conduit or cable trays, and wiretapping sensors.
Practitioner Notes
Transmission media — network cabling, fiber optic lines, and wireless access points — need physical protection to prevent wiretapping, signal interception, or physical damage that could disrupt communications.
Example 1: Run network cabling through conduit or cable trays in secure areas. Avoid running cables through public spaces or areas accessible to visitors. Use locked network closets for patch panels and switches. Install physical port security (port blockers) on unused switch ports.
Example 2: For wireless networks, position access points to minimize signal leakage outside your facility. Use directional antennas where possible and reduce transmit power to cover only required areas. Conduct periodic wireless surveys to detect rogue access points using tools like NetStumbler or Ekahau.