Resolution:
(See SmartSockets User's Guide, Chapter 2 "Connections", Figure 2 to see a diagram of the client buffers mentioned below).
Actually message priority buys you very little. A publisher constructs a message, changes the message priority of the message and then publishes the message. The message goes into the publisher's write buffer and is flushed to its socket buffer. The message is then received by RTserver where it is placed into the write buffer in RTserver which is associated with the connection for the subscribing RTclient, and then pushes it out the the RTclient's socket buffer. When the RTclient performs a TipcSrvMsgRead the message moves into the receiving RTclients read buffer and then into its message queue. It is *here* in the messages queue of the receiving process where the message can be reordered according to its priority and the priority of other messages in this queue. The message at the head of the queue is the next to be processed. (This is how GMD messages can be potentially lost. A message with a higher priority than other messages and with a higher message sequence number can leap to the front of this queue. All messages behind this message in the queue will have lower message sequence numbers and will be discarded by the receiving client). Again, message priority only comes into play at the very end of a message's total route from publisher to receiver.

What does setting of the message priority field in the header of a message buy me?