Tc is used to configure Traffic Control in the Linux kernel.
Traffic Control consists of the following:
SHAPING
When traffic is shaped, its rate of transmission is under
control. Shaping may be more than lowering the available
bandwidth - it is also used to smooth out bursts in
traffic for better network behaviour. Shaping occurs on
egress.
SCHEDULING
By scheduling the transmission of packets it is possible
to improve interactivity for traffic that needs it while
still guaranteeing bandwidth to bulk transfers. Reordering
is also called prioritizing, and happens only on egress.
POLICING
Whereas shaping deals with transmission of traffic,
policing pertains to traffic arriving. Policing thus
occurs on ingress.
DROPPING
Traffic exceeding a set bandwidth may also be dropped
forthwith, both on ingress and on egress.
Processing of traffic is controlled by three kinds of objects:
qdiscs, classes and filters.
