Dear product manager, Glad to know you are in VoIP field with high reputation.This is Janet. We specialize in developing and manufacturing IPPBX & VoIP Gateway& Fax server for more than 8 years and hope to find a way to cooperate with you! Our IPPBX is modular, scalable and flexible, embedded hybrid IPPBX catering for SMBs,supporting PSTN, GSM, SIP(IAX2) trunks with FXS/FXO /BRI/PRI(ISDN) ports,perfectly compatible with almost every brands of IP Phone, such as Yealink, Snom, Grandstream, Cisco, linksys, Aastra etc. Our Analog/GSM/BRI/PRI Gateway support SIP and IAX, fully integrated with Elastix, FreePBX, Asterisk, Lync Server, 3CX. More details? Call me or send me E-mail! Looking forward to hearing from you soon. Best Regards, Janet Ouyang Account manager Tel.: 0086-592-5503309 (Ext:6268）; Fax: 0086-592-5503307; Mobile：0086-18250832577; E-mail: janet(a)voip-index.com