Enhanced visibility and hardening guidance for communications infrastructure

Executive Summary: U.S. and allied security agencies warn that PRC-affiliated threat actors conducted a broad cyber espionage campaign compromising major global telecommunications networks; the advisory notes these compromises leveraged known infrastructure weaknesses (no novel zero‑day activity reported) and delivers extensive recommendations for visibility, monitoring, configuration hardening, protocol security, access control, and Cisco-specific mitigations to reduce risk to communications providers and related enterprises.