Switch fabric is a network topology in which network connection points or nodes interconnect via one or more network switches. It is sometimes used to refer collectively to all the switching hardware and software in a network. The main advantage over basic Ethernet is a higher throughput compared to a standard Ethernet because it spreads the network traffic across multiple physical links.

The most common switch fabric is crossbar switches, which look like a grid and allow any input to transmit data to any output at their full bandwidth at any given time. However, if multiple ports (i.e. 1 and 2) wanted to pass traffic to the same destination port (i.e. 3), they would share port 3’s fabric connection bandwidth.

To control the input process to the chip, current theory is that using buffers that hold a small numbers of frames will optimize the overall performance of the fabric. The buffer is an amount of memory that is synchronized and managed by the fabric CPU, which is known as the fabric arbitration. This fabric arbitration can detect any collisions, pause the data frame in a buffer and wait for the collision to clear. The frame can then be forwarded once the output is free.

The performance of the switch fabric is determined by its ability to, without collision, forward as many frames over the available circuits as possible.