NAC (Network Access Control)

Network Access Control restricts which devices and users can connect to a network and what they can reach once connected, enforced at the switch port (802.1X), wireless (WPA2/3-Enterprise), or VPN concentrator. Modern NAC integrates posture assessment (patch level, EDR presence) and dynamic VLAN assignment, and is a baseline control for Zero Trust architectures.

Categories: Radio Access NetworkSecurity ControlsIoT

NAC in context

The radio access network is the layer where mobile devices attach to the operator's infrastructure. Attacks in this layer include IMSI catching, rogue base stations, downgrade attacks and jamming, and defenses hinge on mutual authentication, integrity-protected signaling and Open RAN supply-chain hygiene.

Security controls in telecom span signaling firewalls (SS7/Diameter/GTP screening at the network edge), transport encryption (IPsec, TLS, PRINS), identity and access on OSS/BSS, and monitoring at both the packet and log level. Controls are audited against GSMA FS.11/FS.19/FS.20/FS.36 and, in Europe, NIS2 sectoral rules.

To place NAC in the wider telecom-security picture, review Inter-Network Function Authentication, 1G, AP, Cipher, Fronthaul and MAC.

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