The scheduler map and rewrite rules perform the following operations
on outgoing packets:
Scheduler maps are applied to interfaces and associate
the outgoing packets with a scheduler and a forwarding class.
The scheduler defines how the packet is treated
in the output transmission queue based on the configured transmit
rate, buffer size, priority, and drop profile.
The buffer size defines the period for which the packet
is stored during congestion.
The scheduling priority and transmit rate determine the
order in which the packet is transmitted.
The drop profile defines how aggressively to drop packets
that are using a particular scheduler.
Output policers meter traffic and might
change the forwarding class and loss priority of a packet if a traffic
flow exceeds its service level.
The rewrite rule writes information to the packet
(for example, EXP or DSCP bits) according to the forwarding class
and loss priority of the packet.
