H3C Technologies H3C S12500 Series Switches - Manual (Page 12)

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Figure 3 OpenFlow forwarding workflow
Table-miss flow entry
Every flow table must support a table-miss flow entry to process table misses. The table-miss flow entry
specifies how to process packets that were not matched by other flow entries in the flow table.
The table-miss flow entry wildcards all match fields (all fields omitted) and has the lowest priority 0.
The table-miss flow entry behaves in most ways like any other flow entry.
Group table
The ability for a flow entry to point to a group enables OpenFlow to represent additional methods of
forwarding. A group table contains group entries.
Figure 4 Group entry components
A group entry contains the following fields:
• Group Identifier—A 32 bit unsigned integer uniquely identifying the group.
• Group Type—Type of the group:
{
All—Execute all buckets in the group. This group is used for multicast or broadcast forwarding.
{
Select—Execute one bucket in the group.
{
Indirect—Execute the one defined bucket in the group.
{
Fast failover—Execute the first live bucket.
• Counters—Updated when packets are processed by a group. S12500 switches do not support
counters for group tables in the current software version.
• Action Buckets—An ordered list of action buckets, where each action bucket contains a set of
actions to execute and associated parameters.
Meter table
Meters enable OpenFlow to implement various simple QoS operations, such as rate-limiting. A group
table contains meter entries.
Figure 5 Meter entry components