We recently formed a partnership with another company that is also using Openfire and Spark. We would like the employees in the call centers of our company and theirs to be able to talk to each other through Spark. Is there a link that can be created between our two servers? What kind of control would we have over who can talk to who on each side? Do we have to create users in CompanyA’s AD for all the people in CompanyB we want to be able to see or is there a way around that?