Glad to know you are on the market for Telecommunication products. Yeastar have MyPBX which can support ISDN BRI,PRI,GSM,PSTN,VOIP  and ANALOGUE LINES right now. MyPBX is CE/TBR21/FCC certificated. The most significant feature of MyPBX is easy to use, stability and reliability and affordable price.Contact me, please!