Prio And Wrr Queues - HP bh5700 User Manual

OpenArchitect switch though, because the normal case is for packets to be switched in hardware.
For that reason, zqosd must be used to shadow tc configuration into hardware. Like
zfilterd, zqosd works with ztmd, which provides the actual hardware interaction.
If ztmd is not already running, start it:, then initiate the zqosd daemon with no parameters:
ztmd
zqosd
Now, repeat the same tc command as before, to install a packet-limited FIFO queue:
tc qdisc add dev zhp0 handle 100:0 root pfifo limit 32
When this command is processed, zqosd detects the state change and generates output.
For each port belonging to zhp0, the queue size has changed to 32 packets. Under the default
switch configuration, all ports other than the CPU port belong to zhp0; so all queues other than
the CPU queue are affected.
As before, remove the tc configuration with the command:
tc qdisc del dev zhp0 root
Note that zqosd detects this state change. In fact, examining the CoS configuration on the
switch reveals that the queue sizes have reverted to their default values.
The byte-limited FIFO queue case differs only slightly from the packet-limited FIFO case. The
syntax is almost identical. In hardware the limit is based on 128 byte cells. The specified byte
limit is divided by 128 to determine the cell limit. Always specify a byte limit of at least 128
bytes to avoid setting the queue length to zero.
For example, to set the byte limit for zhp0 to 4096,
tc qdisc add dev zhp0 handle 100:0 root bfifo limit 4096
Tear down any installed rules before proceeding with the next example:
tc qdisc del dev zhp0 root

PRIO and WRR queues

The FIFO examples used a single queue for each interface. In fact, the Ethernet Switch Blade
fabric switch is capable of attaching 1 to 8 queues to each port, with either priority or weighted
round robin (WRR) scheduling, and classification based on a priority map.
Ethernet Switch Blade User's Guide
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