Many VPN clients do have keep-alive settings, and you could artificially generate traffic on your end to achieve a similar effect, but many times, timeouts are not under your control, as they're caused by something "out there" that temporarily causes packet drops or other forms of extensive delays.
Solved: Keepalive in VPN site to site tunnel - Cisco Community Keepalives or DPD packets are used to sense the other side of the tunnel and make sure its up/down. This allow the site to drop the SA if needed (and not wait until the idle timeout expires). The IPsec tunnels have an idle timeout for phase 1 SAs and phase 2 SAs for security reasons. Normally you don't want the tunnel to be up if not used. Troubleshoot VPN Tunnel Inactivity or Instability Issues Jun 20, 2019 Using the IPSec auto-negotiate and keepalive options
How can I configure a main mode VPN between a SonicWall
An idle tunnel client connection carries only keepalive traffic, which is a small message exchange of one byte per second between the client and server. For regular tunnels, the server sends the Keepalive every 300 seconds and for ESP based tunnel it is the UDP Keepalive interval of 20 seconds. So any latency beyond that would cause problems. IPSec is designed to terminate the tunnel if there is no traffic so if you want to keep the tunnel up, you'll need to generate traffic that matches the crypto map somehow. IKE keepalives are a bit of a misnomer. They detect when the tunnel is down and then you can initiate another tunnel as a backup quicker.
Enable the option if you want the tunnel to be automatically renegotiated when the tunnel expires. Autokey Keep Alive Select the check box if you want the tunnel to …
Using the IPSec auto-negotiate and keepalive options The Keepalive option ensures that a new SA is negotiated even if there is no traffic so that the VPN tunnel stays up. To enable Keepalive - Web-based manager. Go to VPN > IPSEC > Auto Key (IKE). Select the Edit icon for your phase 2 configuration. Select Advanced. Select Autokey Keep Alive. Select OK. To enable Keepalive - CLI. config vpn ipsec phase2 edit