Configuring CoS Drop Profile (NSM Procedure)

Drop profiles provide a congestion management mechanism that enables a switch or routing platform to drop the arriving packets when queue buffers become full or begin to overflow. Drop profiles define the meanings of loss priorities. When you configure drop profiles you are essentially setting the value for queue fullness. The queue fullness represents the percentage of the memory used to store packets in relation to the total amount of memory that has been allocated for that specific queue. The queue fullness defines the delay-buffer bandwidth, which provides packet buffer space to absorb burst traffic up to the specified duration of delay. Once the specified delay buffer becomes full, packets with 100 percent drop probability are dropped from the tail of the buffer.

You specify drop probabilities in the drop profile section of the CoS configuration hierarchy and reference them in each scheduler configuration. By default, if you do not configure any drop profile then the drop profile that is in effect functions as the primary mechanism for managing congestion. In the default tail drop profile, when the fill level is 0 percent, the drop probability is 0 percent. When the fill level is 100 percent, the drop probability is 100 percent.

To configure drop profiles in NSM:

  1. In the navigation tree, select Device Manager > Devices.
  2. Click the Device Tree tab, and then double-click the device for which you want to configure drop profiles.
  3. Click the Configuration tab. In the configuration tree expand Class of Service.
  4. Select Drop Profiles.
  5. Add or modify the drop profiles as specified in Table 200.
  6. Click one:
    • OK—Saves the changes.
    • Cancel—Cancels the modifications.

Note: After you make changes to a device configuration, you must push that updated device configuration to the physical security device for those changes to take effect. You can update multiple devices at one time. See Updating Devices section in the Network and Security Manager Administration Guide for more information.

Table 200: Drop Profile Configuration Fields

Option

Function

Your Action

Drop Profile

Name

Specifies the drop profile name.

  1. Click the New button or Edit button in the Drop Profile interface.
  2. Enter the drop profile name in the Name box.

Comment

Specifies the comment for the drop profile.

  1. Click the New button or Edit button in the Drop Profile interface.
  2. Enter the comment for the drop profile in the Comment box.

Fill Level

Name

Specifies the fill level for the drop profile.

  1. On Drop Profile interface click the New button or select a profile and click the Edit button.
  2. Expand the Drop Profile tree and select Fill Level.
  3. Click the New button or select a fill level and click the Edit button.
  4. Select a value from Name list.

Comment

Specifies the comment for the fill level

  1. On the Drop Profile interface click the New button or select a profile and click the Edit button.
  2. Expand the Drop Profile tree and select Fill Level.
  3. Click the New button or select a fill level and click the Edit button.
  4. Enter a comment in the Comment box.

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