Help understanding nginx proxy

[aarjan]

In nginx proxy setup, https://github.com/surevine/openfire-docker-compose/blob/master/proxy/docker-compose.yml

I cannot proxy xmpp connection from client at port: 55222 through nginx.
Client connection only works directly connecting to port 5222 of openfire.

Please help me understand if only nginx is exposed to internet or both openfire & nginx is open for internet and client connection?
https://github.com/surevine/openfire-docker-compose/blob/master/proxy/README.md