VPN on the customer’s network
The first option is to use the VPN already managed by the customer. This is relevant when the site has an IT team, a clear access policy and an operational VPN service. The technician is then given the appropriate access rights.
However, this model depends entirely on the customer’s organisation. For an integrator maintaining dozens of different sites, procedures, accounts and technologies may vary from one site to another.
Industrial router with a remote service
Many industrial routers provide VPN connectivity or a cloud portal. They are very well suited to installations requiring monitoring or regular access. Depending on the solution and services used, licences, subscriptions or connectivity plans may be added.
For equipment that must remain permanently accessible, this approach makes sense. For a few interventions per year, the cost of keeping access permanently available should be weighed against actual usage.
Temporary VPN through a cellular connection
Another approach is to establish the tunnel only when required. The cellular link allows the gateway installed on site to reach a remote server without requiring an inbound public IP address or an open port on the customer side.
The tunnel can then be created for the duration of the intervention and removed afterwards. This reduces the attack surface and is well suited to occasional maintenance.
Which model should you choose?
If access is required daily, permanent infrastructure may be the most convenient. If the customer already has a well-managed VPN, there is generally no reason to bypass it. However, for varied, isolated or rarely maintained sites, an independent solution activated on demand can greatly simplify interventions.
RescueLAN is positioned specifically for this last scenario: providing temporary remote access through its own 4G/LTE link, without requiring the technician to configure a VPN.