... realize flow media conversion between the IP and PSTN.Large port access gateway Standard SIP protocols Standard G.723.1,G.729A ... /B,PCM A/U code Call forwarding, Call hold, Caller ID, DND ... , ETSI,BT,NTT, and, DTMF-based CIDPolarity ReversalYesHomologationSafetyULComplianceFCC,CE Dinstar 32 Port FXS SIP ATA Gateway