Why would you buy products that are not supported? Why not buy second hand Cisco AS5300 AS5350 or AS5400 something that really works.Use equipment that is certified in HUNDREDS of countries and has been tested to work & has software upgrades readily available? It is fairly easy to find a Cisco Certified technician who can upgrade your hardware & it works each and every day. You can use the Cisco PGW2200 for SS7/C7. There are stable billing systems & if you know how to implement the Cisco IP-to-IP Gateway with a radius billing sytstem & SER you are set. If you have any questions I am happy to answer them I have plenty of diagrams I can email you for VOIP network designs, no problem Cisco CCNA CCIE