passthru

Passthru refers to a method of data transfer or access where information bypasses intermediate processing or security layers. In computing, a passthru mechanism allows data to flow directly from a source to a destination without being modified, filtered, or inspected. This can be applied in various contexts, such as network traffic, device access, or storage operations.

In networking, a passthru port on a switch or router might forward incoming packets to an outgoing port without performing any routing or inspection. This is often used for monitoring purposes or to connect multiple devices in a chain. Similarly, a firewall might have a passthru mode that allows certain traffic to flow unimpeded.

For hardware, passthru can enable a virtual machine to directly access a physical device, such as a graphics card or a storage controller. This bypasses the host operating system's drivers and virtualization layer, potentially improving performance for demanding applications. This is commonly known as hardware passthrough or direct device assignment.

In the context of payments, a payment gateway might offer passthru functionality, allowing sensitive cardholder data to be handled by a third-party processor directly, rather than being processed through the merchant's own systems. This can help merchants reduce their PCI DSS compliance burden. The core idea across these applications is the direct, unadulterated flow of data or access to resources.