Policer Bandwidth and Burst-Size Limits
Table 1 lists each of the Junos OS policer types supported. For each policer type, the table summarizes the bandwidth limits and burst-size limits used to rate-limit traffic.
Policer Type |
Bandwidth Limits |
Burst-Size Limits |
---|---|---|
Single-Rate Two-Color Policer | ||
Defines a single rate limit: a bandwidth limit and an allowed burst size for conforming traffic. For a single-rate two-color policer only, you can specify the bandwidth limit as a percentage value from 1 through 100 instead of as an absolute number of bits per second. The effective bandwidth limit is calculated as a percentage of either the physical interface media rate or the logical interface configured shaping rate. |
M and T Series routers:8000..100000000000 MX Series routers:8000..18446744073709551615 |
M, MX, and T Series routers:1500..10000000000 |
1..100 percent |
||
Single-Rate Three-Color Policer | ||
Defines a single rate limit: a bandwidth limit and an allowed burst size for conforming traffic. Also defines a second, larger burst size. This second burst size is used to differentiate between two categories of nonconforming traffic (yellow or red). |
M and T Series routers:1500..100000000000 MX Series routers:8000..18446744073709551615 |
M, MX, and T Series routers:1500..100000000000 |
M, MX, and T Series routers:1500..100000000000 |
||
Two-Rate Three-Color Policer | ||
Defines a committed rate limit: a bandwidth limit and an allowed burst size for conforming traffic. Also defines a peak rate limit: a second, larger burst size and a second, higher bandwidth limit. These additional rate-limit components are used to differentiate between two categories of nonconforming traffic (yellow or red). |
M and T Series routers:1500..100000000000 MX Series routers:8000..18446744073709551615 |
M, MX, and T Series routers:1500..100000000000 |
M and T Series routers:1500..100000000000 MX Series routers:8000..18446744073709551615 |
M, MX, and T Series routers:1500..100000000000 |
|
Hierarchical Policer | ||
Defines two policers, each with a bandwidth limit and an allowed burst size for conforming traffic. Different policing actions are applied based on whether the packets are classified for expedited forwarding (EF) or for a lower priority. Rate-limits ingress Layer 2 traffic at a SONET physical or logical interface hosted on supported routing platforms only. |
M40e, M120, and M320 (with FFPC and SFPC) edge routers and T320, T640, and T1600 core routers with Enhanced Intelligent Queuing (IQE) PICs:32000..50000000000 MX Series routers:8000..18446744073709551615 |
M40e, M120, and M320 (with FFPC and SFPC) edge routers and T320, T640, and T1600 core routers with Enhanced Intelligent Queuing (IQE) PICs:1500..2147450880 |
On some platforms such as EX2300, packets with smaller frame size create additional headers which results in more traffic. For calculating bandwidth of incoming traffic, these platforms consider packet data and packet headers. The additional headers plus data can cause the traffic rate to exceed the configured policer bandwidth-limit and cause drops. So ensure to take into consideration this additional header traffic when configuring policer bandwidth-limit and burst-size-limit for such platforms.