[ovs-dev] faq: Expand on answer about packet buffering removal.

Submitted by Ben Pfaff on March 17, 2017, 3:16 p.m.

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Message ID 20170317151606.31912-1-blp@ovn.org
State New
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Commit Message

Ben Pfaff March 17, 2017, 3:16 p.m.
Signed-off-by: Ben Pfaff <blp@ovn.org>
---
 Documentation/faq/openflow.rst | 8 ++++++++
 1 file changed, 8 insertions(+)

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diff --git a/Documentation/faq/openflow.rst b/Documentation/faq/openflow.rst
index 376e64eb4482..214e38e6a9aa 100644
--- a/Documentation/faq/openflow.rst
+++ b/Documentation/faq/openflow.rst
@@ -462,6 +462,14 @@  What's going on?
     messages and will send an error response if any other value of this field
     is included in a "packet-out" or a "flow mod" sent by a controller.
 
+    Packet buffers have limited usefulness in any case.  Table-miss packet-in
+    messages most commonly pass the first packet in a microflow to the OpenFlow
+    controller, which then sets up an OpenFlow flow that handles remaining
+    traffic in the microflow without further controller intervention.  In such
+    a case, the packet that initiates the microflow is usually small, which
+    means that the switch sends the entire packet to the controller and the
+    buffer only saves a small number of bytes in the reverse direction.
+
 Q: How does OVS divide flows among buckets in an OpenFlow "select" group?
 
     A: In Open vSwitch 2.3 and earlier, Open vSwitch used the destination