The Skype for Business Example Configuration provides you with a step by step Skype for Business Configuration using TCP with Free/Pro SBC systems, using the Web Portal configuration tool. Complete general installation configuration steps, before you begin configuring your specific scenario. Used Protocols: SIP/UDP for ITSP SIP Trunk, SIP/TCP for S4B Front End Server
You can check the following link for step by step guide https://docs.telcobridges.com/tbwiki/FreeSBC:Skype_for_Business_Configuration:Example_A