Juniper POLICY MANAGEMENT - CONFIGURATION GUIDE V11.1.X Configuration Manual page 92

JUNOSe 11.1.x Policy Management Configuration Guide
A rate limit has one of the four preceding actions configured for each possible result:
committed, conformed, and exceeded. (Transmit unconditional is not allowed as an
exceeded action.) The action taken depends only on the result of that rate limit, its
rates, burst sizes, and current token state. In addition, the rate limit assigns a color
to the packet, depending on both the result of the rate limit and the packet's incoming
color. The final color after a packet has finished traversing a rate-limit hierarchy is
a function of all the rate limits that owned the packet.
Policy actions are processed in the following order:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
The mark action is the last action that occurs, after parent-group, so that the
color-mark profile can mark the packet with the final color from the hierarchy.
66
Hierarchical Rate Limits Overview
its actions to the packet. The transmit conditional option is the same as
connecting the two rate limits in series.
Transmit unconditional Sets the packet color to the result calculated by the rate
limit, retains ownership of the packet, and forwards the packet to the next rate
limit. Later rate limits only decrement their current token counts by the packet
length but do not otherwise affect the packet, either by changing its color or
applying their actions to it. Although the packet is not affected, the remaining
rate limits change because the token counts are reduced, making them more
likely to make other packets conformed or exceeded. Transmit unconditional is
not allowed as an exceeded action.
After the transmit-unconditional completes, the packet traverses to the end of
the hierarchy. Because ownership of the packet has been retained, no rate limit
further down can apply its actions to it. Some of the later rate limits might already
have very low token counts, which must still be decremented when processing
a transmit-unconditional packet (if necessary, by making the token count
negative). Negative token counts enable the remaining rate limits to restrict the
total traffic through them to their peak rate (over a large enough averaging
interval, which is a function of rates and burst sizes only). Transmit unconditional
packets traversing the rate-limit hierarchy reduce the number of tokens available
for other packets.
log
filter
traffic class
user packet class
next hop
rate limit
color status
color action
parent group
mark