xon (Input Congestion Notification)
Syntax
xon value;Hierarchy Level
[edit class-of-service congestion-notification-profile profile-name input dscp code-point code-point-bits] [edit class-of-service congestion-notification-profile profile-name input ieee-802.1 code-point code-point-bits]
Description
Specifies XON threshold offset cells for resuming transmission from the dynamic shared buffer.
Each port can have lossy and lossless queues. You assign forwarding class sets (priority groups) to all the lossless queues at ingress. This enables transmitting priority-based flow control (PFC) frames in case of any congestion at the egress queues. Lossless priority groupgs (PGs) get their ingress buffers from the lossless service pool. The PGs dynamically access these buffers based on the alpha value configured. When the ingress shared occupancy reaches its limit, the corresponding PG transmits the PFC frames to the egress peer so that peer can stop transmitting packets. This limit is called XOFF and is not configurable.
The PFC XON threshold is the ingress port's PG shared buffer limit at which the ingress port's egress peer resumes transmitting packets after a brief PAUSE because of the PFC message sent by this ingress port.
You cannot configure the PFC XON threshold without configuring PFC for the congestion notification profile.
Options
xon value |
XON threshold offset cells for resuming transmission from the dynamic shared buffer. Range: 0-100000 Default: 20 |
Required Privilege Level
interface—To view this statement in the configuration.
interface-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Evolved 22.3R1 for QFX5220 devices.