Securing Out-of-Band (OOB) Access with Zscaler Cellular

Securing Out-of-Band (OOB) Access with Zscaler Cellular

In an environment where uninterrupted access to critical infrastructure can define operational success or failure, Out-of-Band (OOB) access is a necessity, not a luxury. Yet, many enterprises still rely on legacy approaches—most often traditional VPNs or complex cellular deployments with Private APNs—that introduce new risks and operational burdens as environments expand and regulatory requirements become stricter.

The core challenge with these conventional solutions is two-fold: expanded attack surfaces and growing complexity. VPN-based OOB setups inherently broaden network exposure, providing overly permissive access that can swiftly be exploited for lateral movement, ransomware, or advanced persistent threats. At the same time, as organizations adopt cellular as an OOB option, the shift to Private APNs and fragmented device management often results in an intricate web of routing policies, access controls, and siloed monitoring—ultimately impeding real-time visibility and threat response.

Addressing these concerns requires a fresh approach. Zscaler Cellular delivers precisely that by eliminating traditional VPN and Private APN dependencies, instead providing secure, policy-driven connectivity rooted in Zero Trust principles. With internet containment as a foundational design, OOB networks remain insulated from external threats. Granular, identity-based access controls ensure users and devices can only reach authorized applications or assets, with built-in prevention of lateral movement across network segments or sites.

In addition to these robust access controls and segmentation, the ability to manage and monitor the entire OOB environment from a central point is equally critical. Zscaler Cellular addresses this by providing unified SIM oversight, real-time monitoring, and actionable analytics through a single, centralized platform. This enhanced visibility allows teams to troubleshoot efficiently, maintain compliance, and scale operations without added complexity—even as the OOB footprint grows.

This transformation is more than theoretical. In practice, organizations have leveraged Zscaler Cellular to move from cumbersome, high-risk OOB deployments to infrastructures marked by agility, resilience, and sharply reduced risk. 

A prime example of this transformation comes from a leading consulting firm that faced growing challenges with their legacy OOB operations. Despite adopting cellular connectivity, reliance on public internet and Private APNs led to fragmented visibility, operational complexity, and heightened exposure to emerging threats. Regulatory requirements—including Zero Trust mandates from authorities like the ACSC—made a robust shift essential. By adopting Zscaler Cellular, the firm replaced cumbersome architectures with a secure-by-design solution that delivered granular traffic control, centralized oversight, and resilient, always-on connectivity. Combined with Zscaler Internet Access (ZIA) and Zscaler Private Access (ZPA), Zscaler Cellular reinvented their OOB access into a secure, scalable architecture defined by simplicity, resilience, and the agility needed to support evolving business demands.

As edge ecosystems and remote management demands continue to expand, securing OOB connectivity with a Zero Trust approach is fast becoming an industry best practice. Zscaler Cellular redefines what’s possible—making OOB simple, scalable, and inherently secure for organizations determined to stay ahead of both business and cybersecurity challenges.

Any enterprise concerned with critical infrastructure reliability and compliance should now consider if their OOB access model is advancing their security objectives—or hindering them. The shift to a Zero Trust, cloud-enabled architecture for OOB connectivity isn’t just a technical update; it’s a strategic imperative for the modern enterprise.

Discover how Zscaler Cellular can transform your organization’s connectivity and security. Book your live demo now and see it in action!