Supported Platforms
Configuring Dynamic Shaping Parameters to Account for Overhead in Downstream Traffic Rates
You can configure the overhead accounting feature to shape downstream traffic based on either frames or cells.
You can also account for the different byte sizes per encapsulation by configuring a byte adjustment value for the shaping mode.
This feature is supported on MPCs on MX Series routers.
To configure the overhead accounting feature in a dynamic profile:
- Do one of the following to configure the shaping mode:
- Specify the shaping mode.
Frame shaping mode is enabled by default.
[edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-nameuser@host#set overhead-accounting (frame-mode | cell-mode) - Configure a variable for the shaping mode.[edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-nameuser@host#set overhead-accounting $junos-cos-shaping-mode
- Specify the shaping mode.
- (Optional) Do one of the following to configure the byte
adjustment value:
- Specify a byte adjustment value.[edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-nameuser@host#set overhead-accounting bytes byte-value
- Configure a variable for the byte adjustment.[edit dynamic-profiles profile-name class-of-service traffic-control-profiles profile-nameuser@host#set overhead-accounting bytes $junos-cos-byte-adjust
Best Practice: We recommend that you specify a byte adjustment value that represents the difference between the customer premise equipment (CPE) protocol overhead and B-RAS protocol overhead.
The available range is –120 through 124 bytes. The system rounds up the byte adjustment value to the nearest multiple of 4. For example, a value of 6 is rounded to 8, and a value of -10 is rounded to -8.
- Specify a byte adjustment value.
