fileStarting in 13.3.0 Boosters have been given some efficiency and priority improvements.
When a booster requests a missing file from up the chain (from another Booster or from the server), it sends them all at once. When it receives a reply that items are missing it removes them from its worklist.
All devices in the connection chain must be 13.3.0+ to use this efficiency feature.
Booster (13.3) → Booster (13.3) → Server (13.3) = New: Single request to all
Booster (13.3) → Booster (13.2) → Server (13.3) = Revert: Multi request for each
Dedicated Booster Ports
This addition allows the boosters to have a priority connection to the server. Meaning, when a booster needs to download a fileset from a server or booster, it can get it, even if the client ports are at capacity.
See Default TCP and UDP Port Usage
Q: How do I know my booster is using the new ports or old ports?
A: You can use netstat command on the booster to see where the boosters upstream is connected to.
netstat -n |grep -E "20019|20017|20015"
tcp 0 0 192.168.1.145:50718 220.127.116.11:20017 ESTABLISHED
tcp 0 0 192.168.1.145:58450 18.104.22.168:20017 TIME_WAIT
tcp 0 1 192.168.1.145:55056 22.214.171.124:20019 SYN_SENT
Note that the "ESTABLISHED" is using the 20017 port. The above example has fallen back to the Default SSL port on the server.