RoIP(Radio over IP) ATA Cross -Network /Talkback 1.bulit in SIP server 2.Rdiao,VoIP,GSM ,Public Announce 3.support NAT ATA Cross-Network VoIP Gateway RoIP-302M /Talkback RoIP(Radio over IP)Key FeaturesOpen Standard VoIP Protocols (IETF SIP V2)Two 10/100 Ethernet for WAN / LAN connectionsSupply dynamic DNS serviceSpeech quality ensured by QoS at the Ethernet and IP layers and comprehensive jitter bufferLine Echo CancellationVLAN and QoS supportNAT Transversal and Router functionsSupport IP voice stream to via a recording serverHighly stable embedded Linux operating system in high performance ARM 9 ProcessorBasic FeaturesTwo RJ-11 FXS port for traditional phone set or PBX's trunk lineSupport three PTT portLEDs for Power, Ready, Status, WAN, PC, FXSCall Forward, Call Hold, Call TransferDial PlanCaller ID

Enhanced Features

Dynamic selection of codecAdvanced jitter bufferAutomatic traversal of NAT and firewallVLAN / QosRouterEcho cancellation for SpeakerphoneComfort noise generation (CNG)Voice activity detection (VAD)Auto provisioning (requires auto provisioning server)On line firmware upgradeMulti-language support: English and Chinese

Supported Standards

ITU: H.323 V4, H.225, H.235, H.245, H.450RFC 1889 - RTP/RTCPRFC 2327 – SDPRFC 2833 – RTP Payload for DTMF Digits, Telephony Tones and Telephony SignalsRFC 2976 – SIP INFO MethodRFC 3261 – SIPRFC 3264 – Offer/Answer model with SDPRFC 3515 – SIP REFER MethodRFC 3842 – A Message Summary and Message Waiting IndicatorRFC 3489 – Simple Traversal of User Datagram Protocol (UDP) Through Network Address Translators (NATs)RFC 3891 – SIP “Replaces” HeaderRFC 3892 – SIP Referred-By Mechanismdraft-ietf-sipping-cc-transfer-04 –  Session Initiation Protocol Call Control - TransferCodec: G.711 (A/µ law), G.729A/B, G.723.1DTMF: RFC 2833, In-band DTMF, SIP INFO