Network Queue in Linux Kernel

In the Linux Kernel TCP/IP stack, packet queues occur between the link and the internet protocol layers. The link layer is responsible for handling physical address of the device (i.e the MAC address), which is responsible for delivering frames across a physical link.

The network queue acts as a link between the two layers. It buffers the frames received from the NIC and sends them to the Network Layer.

The queue is handled by a simple FIFO driver queue, which is a part of the NIC. A queueing discipline (Qdisc) is sandwiched between the driver queue and the Network Layer, to implement various traffic control capabilities. This portion allows the kernel to perform advanced traffic management of the packets.