Oracle ZFS storage network security minimum port needed

"Minimum Needed Ports To provide security on a network, you can create firewalls. Port numbers are used for creating firewalls, and they uniquely identify a transaction over a network by specifying the host and the service.

The following list shows the minimum ports required for creating firewalls:

Inbound Ports

• icmp/0-65535 (PING)

• tcp/1920 (EM)

• tcp/215 (BUI)

• tcp/22 (SSH)

• udp/161 (SNMP)

Additional inbound ports if HTTP file sharing is used (typically it is not):

• tcp/443 (SSL WEB)

• tcp/80 (WEB)

Outbound Ports

• tcp/80 (WEB) "

--------------------------------------------------------------------------------------------------

My questions are:

1. What is tcp/1920 (EM) for?

2. What is tcp/443 (SSL WEB) for?

3. What is tcp/80 (WEB)