Each network connection has two ports (and two IP addresses). Rather than use the term inbound or outbound, I'll use client and server. Example: The client has IP address 10.0.0.1 and the server has IP address 10.0.0.2. The server is running media server on port 1234. The client connects to the server. This creates a single network connection from 10.0.0.1 port 54321 to 10.0.0.2 port 1234.
The 54321 is a random port chosen by the client.
Many places firewall outbound connections to ports other than 80. This means that if you are connecting to a server and your server port is not 80, it may be filtered by your company firewall.
Firewalls do not usually care about client ports, and in fact nobody really cares about client ports, except that they make it easier to understand what is really happening when the terms "inbound" and "outbound" start flying around (oh yeah, and server a minor purpose to allow multiple connections between the same client and server on the same server port, otherwise how would you keep the connections separate?).
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