When deploying DirectAccess, a critical infrastructure component is the Network Location Server (NLS). The NLS is used by DirectAccess clients to determine if they are inside or outside of the corporate network. Based on NLS reachability, the DirectAccess client will decide if it should attempt to establish DirectAccess connectivity to the tunnel endpoints specified by the DirectAccess configuration. If the DirectAccess client can connect to the NLS, it assumes it is inside the corporate network and does not establish DirectAccess connectivity. If it cannot connect to the NLS, the DirectAccess client assumes it is outside of the corporate network and attempts to establish DirectAccess connectivity.
