Passthrough is an option available on a number of electronic devices. Allows the signal to “pass through” the system unaltered. Various forms of pass-through include HDMI, USB, and network pass-through.
What is HDMI Passthrough?HDMI Passthrough is The digital receiver (or AVR) that processes inputs, such as digital audio, obtained from one or more HDMI ports. It can alter the audio signal by using an equalizer or other effects prior to sending the output to the speakers or another unit. In certain instances, it is preferable to leave the signal intact so that it can be interpreted in its original state by another unit. The “passthrough” option—usually located in the audio menu of the AVR—prevents the input signal from being processed.
HDMI “standby passthrough” is a similar but different option available for some AVRs. Allows digital data to flow through a special HDMI port even when the system is in standby mode (plugged in, but not turned on
USB pass-through enables USB peripherals to be linked through one or more devices. A keyboard with a USB port is a common example. You can attach the mouse to the USB port on the keyboard, which then connects to the USB port on the back of the device. USB hubs have the same features, also for several devices.
USB passes through digital data through a computer but does not always have USB power. If the USB device needs electrical power to be worked (or charged), the pass-through device must supply the appropriate wattage. Usually, keyboards with USB power transfer use two USB cables. USB hubs providing USB power can provide an AC adapter.
Passthrough can refer to any device that relays unaltered data to another device on the network. However, it can also apply explicitly to a modem or router that transmits an IP address to a connected computer.
IP passthrough is a setting that switches off the routing features of the system and lets the data pass through to the next connected device. It is similar to “bridge mode,” but it also excludes any firewall functionality or other data processing. IP passthrough removes the need for a translation of the network address (NAT) and assigns the public IP address to the connected computer.
What is a VPN passthrough?
A VPN passthrough is a feature that allows any computer connected to the router to make outbound VPN connections. In other words, it does as it says on the tin – it allows VPN traffic to pass because old VPN protocols, such as PPTP and LT2P (an obsolete variant of IPsec), do not understand and block it.
Even if it’s on your router, it’s not the same as a VPN router. The former is a feature that makes traffic; it does little else on its own. In the meantime, a VPN router, which can be either a hardware computer with a VPN preset on it or a home router with a VPN client that you set up, encrypts your traffic and protects all devices connected to your network.