Pulsar port distribution between clients, proxy, and brokers

[arzhr]

Hi,
I'm currently working on pulsar infrastructure sizing and limits. Could you help me to understand how port repartition is working between clients, proxy and brokers
For instance, with 10 clients connected to 5 topics: how many inbound ports are opened on pulsar proxy machine? 10 or 50?
Same question for brokers behind proxy? Does broker open same number of outbound ports?
Finally: does pulsar mutualize open ports whatever the number of topics?