Nessy

Nessy is an HTML/JavaScript application that communicates with a
backend API using AJAX. Standard HTTP (ports 80 & 443)
communications are required for the application to function.

All of our websites are hosted within a *.nessy.com sub-domain, so we
require all filters and blocks to be lifted for any request/response
to/from *.nessy.com.

Which communication port numbers are required to be open?

Nessy is an HTML/JavaScript application that communicates with a
backend API using AJAX. Standard HTTP (ports 80 & 443).

TCP or UDP or both?

HTTP communicates over TCP and does not need UDP.

Which directions - incoming /outgoing/both?

Data is both incoming and outgoing.