Neutron Quality of Service, or QoS, is a Neutron feature that enables OpenStack administrators to limit and prioritize network traffic through a set of policies for better network bandwidth.
MCP supports QoS policies with the following limitations:
Bandwidth limit for SR-IOV must be specified in Megabits per second (Mbps) and be dividable by 1000 Kilobits per second (Kbps).
All values lower than 1000 KB per second are rounded up to 1 MB per second. Since float numbers are not supported, all values that cannot be divided by 1000 Kbps chunks are rounded up to the nearest integer Mbps value.
QoS rules are supported for the egress traffic only.
The network interface driver must support minimum transmit bandwidth (min_tx_rate).
Minimum transmit bandwidth is supported by such drivers as QLogic
10 Gigabit Ethernet Driver (qlcnic), BNXT Poll Mode driver
(bnxt), and so on.
The Intel Linux ixgbe and i40e drivers do not support
setting minimum transmit bandwidth.
No automatic oversubscription protection.
Since the minimum transmit bandwidth is supported on the hypervisor level, your network is not protected from oversubscription. Total bandwidth on all ports may exceed maximum available bandwidth in the provider’s network.
This section describes how to configure Neutron Quality of Service.