4.1.3 Scheduling

Scheduling is functionality that controls the order in which the frames in each queue will be sent.

The Switch provides the five scheduling types below. The following table describes the scheduling operations:

Table 4-2: Scheduling operation
Scheduling type	Description	Application example
PQ	Complete priority queuing. 12 queues per port. When there are frames in multiple queues, the frames in a higher-priority queue are always sent first. However, queues 12 (Q#12), 11 (Q#11), 10 (Q#10), and 9 (Q#9) are controlled such that each queue has an equal number of frames to be sent.	When traffic priority must be strictly observed
PQ	Complete priority queuing. 4 queues per port. Queues 4 (Q#4) and 3 (Q#3) are controlled such that each queue has an equal number of frames to be sent. When there are frames in queue 4 or 3, the frames in a higher-priority queue are always sent first. When there is no frame in queue 4 or queue 3, queues 2 (Q#2) and 1 (Q#1) are controlled such that each queue has an equal number of frames to be sent.	When traffic priority must be strictly observed
4PQ+8RR	Round robin with top-priority queues. 12 queues per port. When there are frames in multiple queues, the frames in a higher-priority queue are always sent first. However, queues 12 (Q#12), 11 (Q#11), 10 (Q#10), and 9 (Q#9) are controlled such that each queue has an equal number of frames to be sent. If there are no frames in queues 12 to 9, queues 8 to 1 (Q#8~Q#1) control the number of frames to be transmitted equally regardless of the frame length.	When the only traffic is data traffic
4PQ+8ERR	Top-priority queues and weighted (ratio based on the byte count) round robin. 12 queues per port. When there are frames in multiple queues, the frames in a higher-priority queue are always sent first. However, queues 12 (Q#12), 11 (Q#11), 10 (Q#10), and 9 (Q#9) are controlled such that each queue has an equal number of frames to be sent. If there are no frames in queues 12 to 9, queues 8 to 1 (Q#8~Q#1) send frames according to the ratio (z:y:x:w:v:u:t:s) based on the number of bytes set in the queues.	When the top-priority queues are used for video and audio data, and the ERR queue is used for data traffic
4PQ+8WRR	Top-priority queues and weighted (number of frames) round robin. 12 queues per port. When there are frames in multiple queues, the frames in a higher-priority queue are always sent first. However, queues 12 (Q#12), 11 (Q#11), 10 (Q#10), and 9 (Q#9) are controlled such that each queue has an equal number of frames to be sent. If there are no frames in queues 12 to 9, queues 8 to 1 (Q#8~Q#1) send frames according to the number of frames set in the queues (z:y:x:w:v:u:t:s). If the weights of queues 8 to 1 are set evenly, they operate in round robin mode.	When the top-priority queues are used for video and audio data, and the WRR queue is used for data traffic
4PQ+8WFQ	Top-priority queues and weighted fair queuing. 12 queues per port. When there are frames in multiple queues, the frames in a higher-priority queue are always sent first. Queues 12 (Q#12), 11 (Q#11), 10 (Q#10), and 9 (Q#9) are controlled such that each queue has an equal number of frames to be sent. If there are no frames in queues 12 to 9, queues 8 to 1 (Q#8~Q#1) initially send the minimum guaranteed bandwidth for each queue according to the specified weight (minimum guaranteed bandwidth). After sending all queues, a round-robin operation will be performed.	Video as the highest-priority queue, audio, data-related traffic as WFQ queue

The following table describes the scheduling specifications.

Table 4-3: Scheduling specifications
Item		Specifications
Number of queues		12 queues
4PQ+8ERR	Weight setting range of queues 1 to 8	1~127
4PQ+8WRR	Weight setting range of queues 1 to 8	1~15
4PQ+8WFQ	Weight setting range of queues 1 to 8	For details, see "(1) Setting area of WFQ". Make sure that the sum of the minimum guaranteed bandwidths is equal to or smaller than the line bandwidth.
4PQ+8WFQ	The part of a frame to which the minimum guaranteed bandwidth applies	From the MAC header to the FCS header

<Structure of this section>

(1) WFQ setting range

(1) WFQ setting range

The tables below show the setting range for WFQ.

Table 4-4 WFQ Configuration Areas (10BASE-T,100BASE-TX,1000BASE-T,1000BASE-X)
Setting unit #1	Setting range	Increment
Gbit/s	1G	1 Gbit/s
Mbit/s	1M~1000M	1Mbit/s
kbit/s	1000~1000000	100kbit/s^#2
kbit/s	64~960	64kbit/s^#3

#1: 1G is treated as 1000000000, 1M is treated as 1000000, and 1k is treated as 1000.

#2: To set a value of 1000 kbit/s or more, specify the value in units of 100 kbit/s (1000, 1100, 1200...1000000).

#3: To set a value less than 1000 kbit/s, specify the value in units of 64 kbit/s (64, 128, 192...960).

Table 4-5 WFQ Configuration Areas (10GBASE-R,10GBASE-T)
Setting unit #1	Setting range	Increment
Gbit/s	1G~10G	1 Gbit/s
Mbit/s	1M~10000M	1Mbit/s
kbit/s	1000~10000000	100kbit/s^#2
kbit/s	64~960	64kbit/s^#3

#1: 1G is treated as 1000000000, 1M is treated as 1000000, and 1k is treated as 1000.

#2: To set a value of 1000 kbit/s or more, specify the value in units of 100 kbit/s (1000, 1100, 1200...10000000).

#3: To set a value less than 1000 kbit/s, specify the value in units of 64 kbit/s (64, 128, 192...960).

Table 4-6 WFQ Configuration Areas (40GBASE-R)
Setting unit #1	Setting range	Increment
Gbit/s	1G~40G	1 Gbit/s
Mbit/s	1M~40000M	1Mbit/s
kbit/s	1000~40000000	500kbit/s^#2
kbit/s	256~768	256kbit/s^#3

#1: 1G is treated as 1000000000, 1M is treated as 1000000, and 1k is treated as 1000.

#2: To set a value of 1000 kbit/s or more, specify the value in units of 500 kbit/s (1000, 1500, 2000...40000000).

#3: To set a value less than 1000 kbit/s, specify the value in units of 256 kbit/s (256, 512, 768).

Table 4-7 WFQ Configuration Areas (100GBASE-R)
Setting unit #1	Setting range	Increment
Gbit/s	1G~100G	1 Gbit/s
Mbit/s	1M~100000M	1Mbit/s
kbit/s	1000~100000000	500kbit/s^#2
kbit/s	512	512kbit/s^#3

#1: 1G is treated as 1000000000, 1M is treated as 1000000, and 1k is treated as 1000.

#2 If the setting is 1000k or more, specify in 500k increments (1000, 1500, 2000,..., 100000000).

#3 If the setting is less than 1000k, specify only 512.