Traffic management egress buffer thresholds

For egress buffer management in the SLX 9150 device, all ports and all priorities share a buffer pool of approximately 30MB. The buffers are dynamically allocated. If there is only one queue that is congested, it can take up to 66.67% of the shared pool buffer to absorb a large burst. You can view this information as max-bytes through the show tx-queue internet ethernet command. However, as the number of congested queues increases, the shared pool continues to divide. As a result, the number of buffers that a queue can take up continues to become less. You can view the real-time status of the max-bytes that a queue is using by using the show tx-queue internet ethernet command.

For all other devices, during the traffic management (TM) initialization process, TM egress buffer thresholds are configured and set to the values listed in the following tables.The following table shows the egress thresholds for unicast and multicast traffic that are configured during the TM initialization process at the device level.

Table 1. TM egress thresholds on the device
Threshold	Packet descriptor (PD) flow control (FC)	PD Drop	DB (Data buffers) FC	DB Drop
Unicast	6100	6000	6100	6000
Multicast		26000		6000

The following table shows the egress thresholds for unicast and multicast traffic that are configured during the TM initialization process at port level on the device.

Table 2. Local port TM egress thresholds on the device
Threshold	Packet descriptor (PD) flow control (FC)	PD Drop	DB (Data buffers) FC	DB Drop
Unicast priority low	1024	4000	84	6000
Unicast priority high	1024	4000	84	6000
Unicast port	167	6000	167	6000
Multicast priority low		722		7220
Multicast priority high		722		7220
Multicast port		135		1350

Note

The burst size on special CPU ports (202 and 203) is set to 600.