Determining Packet Drop Behavior by Configuring Drop Profile Maps for Schedulers
RED drop profiles take action on outgoing packets. When
tricolor marking is enabled, M320, MX Series, and T Series routers
support four drop-profile map PLP designations: low
, medium-low
, medium-high
, and high
.
Drop-profile maps associate RED drop profiles with a scheduler.
The map examines the current loss priority setting of the packet (low
, medium-low
, medium-high
, or high
) and assigns a drop profile according to these values.
For example, you can specify that all TCP packets with low
loss priority are assigned a drop profile that you name low-drop
. You can associate multiple drop-profile maps with a single queue.
The scheduler drop profile defines the drop probabilities across the range of delay-buffer occupancy, thereby supporting the RED process. Depending on the drop probabilities, RED might drop packets aggressively long before the buffer becomes full, or it might drop only a few packets even if the buffer is almost full. For information on how to configure drop profiles, see RED Drop Profiles for Congestion Management.
By default, the drop profile is mapped to packets with low PLP and any protocol type.
When you configure TCM, the drop-profile map’s protocol
type must be any
.
The map sets the drop profile for a specific PLP and protocol type. The inputs for the map are the PLP and the protocol type. The output is the drop profile. In other words, the map sets the drop profile for each packet with a specific PLP and protocol type exiting the interface. For more information about how CoS maps work, see Mapping CoS Component Inputs to Outputs.
On Juniper Network MX Series 5G Universal Routing Platforms,
T4000 Core Routers, EX Series switches, and PTX Series Packet Transport
Routers, you can configure only the any
option for the protocol
statement.
For each scheduler, you can configure separate drop profile maps for each loss priority.
You can configure a maximum of 32 different drop profiles.
In the following sample configuration, the dp
drop
profile is assigned to all packets exiting the interface with a medium-low
PLP and belonging to any protocol:To configure this drop profile map:
To use this drop-profile map, you must configure the settings
for the dp
drop profile at the [edit class-of-service
drop-profiles dp]
hierarchy level..