Platform Support for Tricolor Marking

In the Juniper Networks JUNOS Software implementation, you can configure four loss priorities (sometimes called four-color marking) instead of three. In spite of the four priorities, the generic name “tricolor marking” still applies because this is the standard form under which all variations are implemented. The software marks the four loss priorities as high, medium-high, medium-low, and low. This allows you to provision even more granular service-level agreements (SLAs) across the DiffServ domain. Tricolor marking can be configured as single-rate or two-rate.

TCM is supported on the following Juniper Networks routers:

M120 Multiservice Edge Routers
M320 Multiservice Edge Routers and T Series Core Routers with Enhanced II Flexible PIC Concentrators (FPCs)
MX Series Ethernet Services Routers (two-rate TCM only)
T640 Core Routers with Enhanced Scaling FPC4

The platforms that support TCM interoperate with other platforms, as shown in Table 14.

Table 14: TCM Platform Interoperation

Packets Sent	Packets Received
From Other Platforms	By Platforms Supporting TCM
low	low
high	medium-high
From Platforms Supporting TCM	By Other Platforms
low	low
medium-low	low
medium-high	high
high	high

You can monitor how packets are marked by issuing the show class-of-service forwarding-table classifier command:

user@host> show class-of-service forwarding-table
classifier

Classifier table index: 33166, # entries: 8, Table type: IEEE 802.1
Entry #   Code point   Queue #    PLP
   0           000        1       2  <---- medium-low
   1           001        2       2
   2           010        2       1  <---- high
   3           011        1       1
   4           100        2       3  <---- medium-high
   5           101        1       3
   6           110        1       0  <---- low
   7           111        2       0