Can we configure the MVP200 to work behind NAT Translation?

Yes, the ports which need to be opened inbound and outbound to the voips depends on the firmware the voip is running. If the voip is running proprietary firmware such as 2.01f then the ports are UDP 5000, 5004-5007, 900 and 902. If the voip is running H.323 firmware such as 2.51x then the NAT device needs to support the H.323 protocol which uses a wide range of dynamic ports.

The H323 ports used by the MultiVOIP is as follows:
H.225 listen port = 1720 (TCP). H.225 client port = Dynamic (16000 - 20000) (TCP).
H.245 listen port = Dynamic (16000 - 20000) (TCP).
H.245 listen port = Dynamic (16000 - 20000) (TCP).
RAS client port = Dynamic (16000 - 20000) (UDP).
RTP port (channel 1) = 5004 (UDP).
RTCP port (channel 1) = 5005 (UDP).
RTP port (channel 2) = 5014 (UDP).
RTCP port (channel 2) = 5015 (UDP).
RTP port (channel 3) = 5024 (UDP).
RTCP port (channel 3) = 5025 (UDP).
RTP port (channel 4 = 5034 (UDP).
RTCP port (channel 4)= 5035 (UDP).
RTP port (channel 5) = 5044 (UDP).
RTCP port (channel 5) = 5045 (UDP).
RTP port (channel 6) = 5054 (UDP).
RTCP port (channel 6) = 5055 (UDP).
RTP port (channel 7) = 5064 (UDP).
RTCP port (channel 7) = 5065 (UDP).
RTP port (channel 8) = 5074 (UDP).
RTCP port (channel 8)= 5075 (UDP).
Proprietary port for master/slave protocol = 5000 (UDP).

Note: This is not a H323 standard). You must make sure the ports that are opened are not set to time out, they must remain open both inbound and outbound at all times.