User Guide > PSFP

Per stream filtering and policing (PSFP)

A Switch or a Host ingress Port that supports PSFP can perform filtering and policing on subsets of frames (Streams) that enters that Port as described in [1]. Note that the Stream gate instance table is currently not supported.

Stream Identities

PSFP takes advantage of the different methods for Stream identification used by Frame Replication and Elimination for Reliability (FRER), see Clause 6 in [2].

Position

This integer value uniquely identifies the specific Stream identification function defined on a specific table row and acts as an index to the table.

Method

Currently, the following methods for performing Stream identification are supported:

Flow [M256]

The name of the flow to match or all flows (this will match everything).

MAC Address [M1][M2]

This parameter defines a source MAC address or a destination MAC address depending on the Stream identification method used.

VLAN [M1][M2]

Specifies the VLAN identifier that must be associated with a received Ethernet frame for the identification method to identify the packet as belonging to the stream. A value of 0 indicates that the VLAN identifier parameter is ignored.

Ports

Identifies which port(s) this identification function is active on. At least one port must be specified.

Stream Filters

This table defines an ordered list of stream filters that specify the filtering and policing actions that will be applied to frames received on a specific stream.

Which Stream identification function that is associated with a received frame, and the priority of the frame, will determine which stream filter is selected to be applied to the frame.

If several stream filters in the table match a specific Ethernet frame, the stream filter that is applied is the one that appears earliest in the ordered list.

Position

This is an integer value that uniquely identifies the stream filter instance and also acts as an index to the table. The ordering of the identifier values defines the ordering of the list of stream filters; smaller identifier values appear earlier in the ordered list.

Identity reference

Used as an index into the Stream Identities table to select the method used for identifying the frames that belong to the stream to which a specific Stream Filter will be applied.

Priority

Specifies the priority that must be associated with a received frame for a particular stream filter to match and be applied to that frame. This can be either of the following:

  1. A single priority value
  2. A wild-card value that matches any priority value

Meter reference

Identifies an instance of a flow metering function and works as an index into the Flow Meter table.

SDU

Specifies the Maximum allowed SDU size; received Ethernet frames that exceed this SDU size are not allowed to pass the stream filter and are discarded. Frames with an SDU size smaller than specified by this parameter pass the stream filter, if they are not rejected by a possible Flow Meter.

Blocked

This checkbox indicates whether the StreamBlockedDueToOversizeFrame function is active or not. If both this and the Blocked Enable checkbox are marked, all frames belonging to the stream will be dropped, that is the stream filter will behave as it would if the maximum SDU size were set to 0 octets. If this checkbox is left unmarked, it has no effect. Note that if any frame is discarded because it exceeds the Maximum SDU size for the stream during a simulation and the Blocked Enable checkbox is marked, then the StreamBlockedDueToOversizeFrame function will also be activated.

Blocked Enable

This checkbox indicates whether the StreamBlockedDueToOversizeFrame function is enabled or disabled.

FlowMeters

This table specifies the operating parameters for each Flow Meter instance. These parameters are specified in Bandwidth Profile Parameters and Algorithm in [3].

Position

This is an integer value that uniquely identifies the flow meter instance and also acts as an index to the table.

CBS (Committed Burst Size)

Expressed as bytes. This parameter limits the maximum number of bytes available for a burst of Service Frames sent at line rate that will be declared Green by the Bandwidth Profile

CIR (Committed Information Rate)

Expressed as bits per second. This parameter limits the average rate in bits per second of Service Frames that will be declared Green by the Bandwidth Profile.

EBS (Excess Burst Size)

Expressed as bytes. This parameter limits the maximum number of bytes available for a burst of Service Frames sent at line rate that will be declared Yellow by the Bandwidth Profile.

EIR (Excess Information Rate)

Expressed as bits per second. This parameter limits the average rate in bits per second of Service Frames that will be declared Yellow by the Bandwidth Profile.

CA (Color Aware)

This parameter indicates whether the color-aware or color-blind property is employed by the Bandwidth Profile.

CF (Coupling Flag)

This parameter determines whether or not overflow tokens not used for Service Frames declared Green can be used as Yellow tokens.

DOY (Drop On Yellow)

If this checkbox is marked, yellow frames will be discarded.

MAFR (Mark All Frames Red)

This checkbox indicates whether the MarkAllFramesRed function is active or not. If both this and the MAFRE checkbox are marked, all frames will be discarded. If this checkbox is left unmarked, it has no effect. Note that if the operation of the flow meter causes any frame to be discarded during a simulation, then the MarkAllFramesRed function will also be activated.

MAFRE (Mark All Frames Red Enable)

This checkbox indicates whether the MarkAllFramesRed function is enabled or disabled.

References

  1. IEEE Std 802.1Q-2018
  2. IEEE Standard 802.1CB-2017
  3. MEF Technical Specification - MEF 10.3