Is it any step by step instruction to guide me set up from the Synway SHT-4B/USB to Carousel Virtual FXO gateway to Axon Virtual PBX to Express Talks? It is an in-house network environment, no external internet connection. only 1 CO lines, six softphones (Express Talk) start from beginning. If this setting is work fine, the facility would increase up to 3 CO lines and 4 more SIP Voip phone sets in the future. Please ASAP feel free to contact me at "email@example.com" with subjust heading as "NCH-PBX-Forum", if your instruction is work, you would get something as return.