[Features] 4FXS/4FXO/2FXS + 2FXO, continuous choice supported Codec: G. 711A-/U-law, G. 723. 1/AG, 729A/B G. 168 (25-64MS) Diffserv, SNTP(SIP version), CNG. TOS. JITTER BUFFER, VAD Intelligent routing; Power-off protection T38, T30 and FRF supported Caller ID checking and displaying supported FSK and DTMF check and generate Busy tone self-learning CNG(Comfort Noise Generation) and value adjustment supported Polarity reversal billing provided Voice record and IVR Programmable Remote management, upgrade and maintenance [Specifications] Unit weight: 1.32 KG Unit dimension: 220X136X32mm