According to Wikipedia: 5222 TCP XMPP client connection (RFC 6120) Official 5223 TCP XMPP client connection over SSL Unofficial 5269 TCP XMPP server connection (RFC 6120) Official 5298 TCP UDP XMPP JEP-0174: Link-Local Messaging / Official XEP-0174: Serverless Messaging 8010 TCP XMPP File transfers Unofficial The port numbers are defined in RFC 6120 § 14.7.
contact list (in XMPP this is called a “roster”) Source: XMPP-IM – RFC 6121 § 1.3: Requirements
This is probably way too basic, but at least it’s technical: https://web.archive.org/web/20170916193014/http://www.adarshr.com/fun-with-xmpp-and-google-talk and the second part, https://web.archive.org/web/20171005104211/http://www.adarshr.com:80/fun-with-xmpp-and-google-talk-part-2 It explains what stanzas are, what types are available and stuff.
I’ve found Openfire to be quite slick and not too much hassle (it’s a Java app). The Redhat package installs to /opt, which I don’t think is great, whereas the Debian package is very clean and “sane”, last time I checked it out. http://www.igniterealtime.org/projects/openfire/index.jsp
I had the same issue, little know and it seems undocumented bug. Try rebooting the server after the you do the install. Worked for me.