Hi,
Since you didn't really specify anything about what type of computer you will be installing it on, I am going to assume a Windows PC.
This document should give you everything you need to know.
http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/jabber/11_8/cjab_b_planning-guide-jabber-118/cjab_b_planning-guide-jabber-118_chapter_01.html
Thanks,
Adam