*astTECS PRI Cards are high performance, cost effective telephony cards available with carrier grade optional hardware echo cancellation. *astTECS E1/T/J1 digital cards are designed to work with Open Source based VoIP platforms such as Asterisk® (e.g. PBX in a Flash®, FreePBX® Elastix®) & FreeSWITCH®. It supports industry standard telephony protocol families. Both line-side, trunk-side interfaces along with advanced call features are supported. Ease of installation (over multiple Linux platforms),Superior voice quality at an unmatched price. Available in PCIe and Universal PCI (5V / 3.3V) form factor 2U form factor capable of installation on rack-mount servers – 2U brackets available on request. Operating Systems : Linux Kernel – 2.4 to Latest. Windows – XP/Vista/Win7 Line Protocols : Voice CAS, MRC/R2 PRI, SS7,HDLC / PPP