The VPN Passthrough feature is usually used if there are devices behind the ATA (Analog Telephone Adapters) that need to set up IPsec tunnels independently. The page allows you to let the Internet Protocol Security (IPSec), Point-to-Point Tunneling Protocol (PPTP) and Layer 2 Tunneling Protocol (L2TP) pass through the firewall on the device.
The objective of this article is to configure the VPN Passthrough settings on SPA122 VoIP device.
• SPA122
• v1.1.0
Step 1. Log in to the web configuration utility and choose Network Setup > Advanced Settings > VPN Passthrough. The VPN Passthrough page opens:
Step 2. Internet Protocol Security (IPSec) provides secure IP communications through authentication and encryption. To allow IPSec tunnels to pass through the ATA, IPSec Passthrough is enabled by default. To disable IPSec Passthrough, click the Disabled radio button.
Step 3. Point-to-Point Tunneling Protocol (PPTP) is the method used to enable VPN sessions through an IP network. To allow PPTP tunnels to pass through the ATA, PPTP Passthrough is enabled by default. To disable PPTP Passthrough, click the Disabled radio button.
Step 4. Layer 2 Tunneling Protocol (L2TP) is a tunneling protocol used to support Virtual Private Networks (VPNs). It does not provide any encryption or confidentiality by itself; it relies on an encryption protocol that it passes within the tunnel to provide privacy. To allow L2TP tunnels to pass through the ATA , L2TP Passthrough is enabled by default. To disable L2TP Passthrough, click the Disabled radio button.
Step 5. Click Submit. The changes are saved and the device is updated.
Note: If the administrator disables passthrough, it will prevent VPN clients from connecting to your network.