Thank you for your advice. Unfortunately, my knowledge of traffic shaping is not comprehensive enough to know how to do that.
I tried using http://doc.pfsense.org/index.php/Traffic_Shaping_Guide, but the document seems incomplete, so many questions are unanswered.
(1) This is for traffic going from LAN to WAN, so would I establish a traffic shaper for the LAN interface or for the WAN interface?
(2) The options the wizard gives me are: Single LAN/Multi WAN, Single WAN/Multi LAN, Multiple LAN/WAN, and Dedicated Links. I have Single LAN/Single WAN, which isn't listed. Which choice is appropriate?
(3) I have the choice to "Enable/disable discipline and its children." I can't find in the documentation what that means.
(4) I can choose HFSC, PRIQ, CBQ, or FAIRQ. PRIQ is described in the documentation, and seems to be what I want. No other choices are described.
Other choices seem to be set up so that I can assign a bandwidth limit to each queue. I don't want to limit the bandwidth. I just want traffic on port 12345 to be lower priority than anything else.
Is there anywhere that this process is described in more detail?
1) On older pfSense 2.0 builds, you set a floating rule without selecting interface OR a rule on the LAN tab. On the newer RC1 builds (you can select Queue as the action), you will want 2 rules, one for the LAN tab and one floating. There are certain issues with matching the traffic both ways and I've found that setting 2 rules, one in floating, one in LAN, will help match the traffic both ways.
2) Choose Single LAN, Multi-WAN. Enter 1 for number of WAN connections when prompted.
3) Use the traffic shaper wizard and ignore that for now.
4) You want PRIQ, this can be set in the traffic shaper wizard. Follow the wizard through, don't select VOIP prioritising unless you have such traffic. For the applications page, select a random application (say HTTP) and set to lower priority.
After you're done with the wizard, head to Firewall -> Rules -> Floating. You will see a rule for HTTP, go ahead and delete the rule. We just needed it so that the shaper will create the lower priority queue for you. Now, head to LAN tab. Add a rule by clicking the '+' Sign at the top right corner.
For protocol, set the appropriate protocol (TCP or UDP) for the RSYNC or SSH service.
For source, you can select 'Single Host', enter the LAN IP of the server making the outbound connection.
For destination, select Any and the port as the port on your destination server (12345 in the example you gave).
Scroll down to Queues then select qAck/ qOtherLow for the queues.
You will be brought to the Rules page again. This time, head to the LAN tab and find the rule you just created. Click the '+' sign beside the rule to duplicate it. Follow the above but set the protocol and destination port as per the 2nd rule you need (SSH if the first rule was Rsync, vice versa). Click save.
Now head to Floating rules, add a new rule. For Action, select 'Queue'. Protocol as per above. Do not select direction and do not select the interface. Just select the destination port and set the queues below and save. Again, duplicate as with the LAN rules.
You should be good to go from there.