Booster ports 20018 and 20019 introduced in 13.3.1. Booster routing relays some client communication through the Booster.
Configuring port 20015 automatically configures port 20017(SSL). 20017 takes priority if available. Do not configure the Client/Booster to use 20017.
Configuring port 20013 automatically configures port 20014(SSL). 20014 takes priority if available. Do not configure the Client/Booster to use 20014.