In a FortiSASE environment, the Unified FortiClient agent is the critical component that fulfills the requirement for " always-on " connectivity and security for remote users.

Persistent Encrypted Tunnels : The Unified FortiClient maintains a persistent, always-on connection to the FortiSASE infrastructure. 4 This is typically achieved through an auto-connect VPN tunnel (SSL or IPsec) that initiates as soon as the user logs into their device and has internet access.

Continuous Security Enforcement : By staying connected to a nearby FortiSASE Point of Presence (PoP), the endpoint ensures that all traffic is inspected. This allows the organization to enforce a consistent security posture—including Web Filtering, Antivirus, and Application Control—regardless of whether the user is at home, in a coffee shop, or traveling.

Zero-Trust Integration : Beyond simple connectivity, the unified agent supports Universal ZTNA . It continuously verifies the identity of the user and the security posture of the device before granting access to specific applications, thereby satisfying modern zero-trust security mandates.

Comparison of Other Components :

SD-WAN on-ramp (B) : Used primarily to integrate existing branch office SD-WAN networks with the SASE cloud for private application access.

Secure Web Gateway (C) : While a feature of the SASE PoP, the agentless SWG deployment (using PAC files) does not provide the same level of " always-on " persistent tunnel protection as the FortiClient agent.

Thin-branch SASE extension (D) : Focused on securing small branch locations (using FortiAP or FortiExtender) where individual client agents may not be deployed on every device.