+ * as necessary if it grows too large for the available memory.
+ *
+ * 'frame' and offset conventions:
+ *
+ * Network frames (aka "packets"): 'frame' MUST be set to the start of the
+ * packet, layer offsets MAY be set as appropriate for the packet.
+ * Additionally, we assume in many places that the 'frame' and 'data' are
+ * the same for packets.
+ *
+ * OpenFlow messages: 'frame' points to the start of the OpenFlow
+ * header, while 'l3_ofs' is the length of the OpenFlow header.
+ * When parsing, the 'data' will move past these, as data is being
+ * pulled from the OpenFlow message.
+ *
+ * Actions: When encoding OVS action lists, the 'frame' is used
+ * as a pointer to the beginning of the current action (see ofpact_put()).
+ *
+ * rconn: Reuses 'frame' as a private pointer while queuing.
+ */