Users Guide

OpenFlow 1721
Collect Port and Queue Status and Statistics
The OpenFlow Controller can collect status and statistics for ports and
queues. When ports are created, Dell EMC Networking OpenFlow Hybrid
sends an OFPT_PORT_STATUS message to the OpenFlow Controller. The
status message is triggered by creation of entries in the Physical Port Table.
The same tables are used for reporting port status information.
The port status is updated by a separate task that periodically polls the status
for all physical ports. To avoid performance issues, the statistics are polled
every 10 seconds for a maximum of 100 interfaces. For physical ports, the
switch also reads the queue statistics for all eight queues at the same time as
it reads the port statistics.
The LAG statistics are reported as a sum of statistics for all active LAG
member ports. This implies that when a port is removed from the LAG, the
statistics counters for the LAG go down. Also, when all ports are removed
from a LAG, the LAG statistics are reported as 0.
Usage Scenarios
The OpenFlow feature is mainly targeted for deployment in a data center
network where devices located in different parts of the network require Layer-
2 connectivity.
The OpenFlow feature enables customers to avoid scaling problems and loops
associated with the Layer-2 network.
The OpenFlow feature can also be used in a research environment, but there
are two limitations that may make the "research" use case less attractive. First,
there is only one OpenFlow instance, meaning that concurrent experiments
are not supported at the switch level. Second, the OpenFlow controller has
complete access to all ports and VLANs; therefore, using the switch for mixed
production and experimental traffic is not advisable.
Eligible Interfaces
The OpenFlow application affects traffic forwarding on physical ports and
LAGs.