Jabber the client application Cisco still supports, not to be confused with the open source XMPP protocol or Jabber.org, requires server applications to function: CUCM-IM&P at minimum and Expressway for Mobile and Remote Access if you want the client to function outside the corporate firewall without VPN access. Candidly, this is a proverbial mountain to climb if you’ve never designed or deployed it before. Hundreds, probably thousands, of pages of documentation that took folks (myself included) years to master. As Leo mentioned, this is not where Cisco is steering customers anymore. It continues to exist - and will for some time - because of the massive install base as well as air-gapped environments that cannot use commercial SaaS solutions. If you truly want to start climbing that mountain, reply saying as much and I’ll pull together a few documentation links for you to start with.
Otherwise, if you’re just looking for a business-class modern chat/calling/screen share/meeting app go check out Webex. You can create a free account, download the app, and collaborate with other users on the platform.
