I was reading about queues and I came across OpenFlow Queues and IEEE 802.1p I would like to know what are the main differences between them, and how they treat the traffic. In other words how they affect the QoS.

Thank you in advance.

2 Answers 2


Although they are both related to quality of service, they are completely different concepts.

IEEE 802.1p is a mechanism (format) for marking "class of service" (CoS) on Ethernet frames. The CoS has eight values (0-7) and is used to signal the relative priority of the frame.

The standard recommends some meaning to the different values (higher is better), but does not define how that traffic should be treated. In other words, the meaning of a particular value and how it affects forwarding in a device is left to the manufacturer. In the Cisco world, you can use the value in class-maps to specify how the traffic might be queued, policed, shaped, etc.

Since 802.1p values are carried in tagged Ethernet frames, they do not persist beyond the layer-2 segment. They are often mapped to DSCP values which are carried in layer 3.

Openflow Queues are a scheduling mechanism for Openflow switches. They are similar in function to queuing mechanisms found on traditional switches. I confess to not having much experience configuring Openflow queues, but more information can be found here.


Ron is correct, 802-1p and OpenFlow are 2 different things,

Here are a few additions.

OpenFlow is an SDN based southbound signaling protocol.

In general, SDN is the separation of control plane and data plane

The architecture consists of the following, a controller, SDN enabled switches and network end devices (servers, hosts, etc)

OpenFlow is used for communication between the controller and the switches, and between the switches to the end devices.

As the basic use case for this protocol is communication between the controller and the devices. This communication may or may not be related to QoS.

For eg. OpenFlow can be used to populate routing tables, resolve ARP requests, etc. It need not be directly related to any QoS mechanisms.

On the other hand, 802-1p is a QoS based standard that classifies traffic in 7 buckets where 7 been the most urgent and 1 been the least urgent.

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