Voice/Fax/Modem over IP (with Payload Type Discrimination) Echo Canceller (ECU) G.165/168 Tx Gain Voice Activity Detection and Tone Detection Unit Rx Gain PSTN Fax Data Pump Unit (FDPU) Interface ITU V.34fax - V.17 V.33 - V.29 V.27ter - V.21 Unit (PIU) Modem Data Pump Unit (MDPU) ITU V.92 V.91 V.90 V.34 V.32bis V.32 V.23 V.22bis V.22 V.21 Voice Codec Unit (VCU) ITU G.711- G.722.1 G.723.1 - G.726 G.727 - G.728 G.729/A/B/E ETSI GSM FR/EFR/AMR Voice Playout Unit (VPU) Packetized Voice Protocol Unit (PVPU) RTP Payload Type Voice (RTP-PTV) AAL2 Fax Protocol Relay Unit (FPRU) ITU T.37 - T.38 (v1, v2) - T.38 RTP Payload Type Fax (RTP-PTF) VoIP Packet Network FoIP Interface Fax Protocol Termination Unit (FPTU) ITU AT Commands (V.25x) T.30 - T.6/T.4/JBIG Image Format Conversion Data Error Correction Unit (DECU) Data Compression Unit (DCU) ITU V.42 MNP2-4 ITU V.44 V.42bis MNP 5 - 10 AT Command Unit (ATCU) ITU V.250 V.251 V.252 V.253 Signaling, Software Integration Management for all the Modules Unit (PNIU) Network Encapsulation Unit (NEU) SLIP PPP RTP Payload Type Modem (RTP-PLM) MoIP http://www.vocal.com © 2001 Technologies, Ltd.