@nagendra You have to upload the picture. . Use
TinyPic - Share the Experience!™
give the link ref here. Not needed now. Any way try.
@onlytest has given it earlier.
in modem 1 page available...Overview of Device Information
Equipment Vendor ZTE
Model No ZXDSL 831AII
Chipset Part No ZXDSL 831AIIV1.0.1i_D18_IN
Chipset Version No E.37.7.37
Firmware Version ZXDSL 831AIIV1.0.1i_D18_IN
If same as above confirm . If not
You can type the details only first four entries and firmware version to see any difference..
(with Nat/portforward function included )firmware version may be available in some russian site/s .
Para two : Do you get a menu page like this ?
http://img91.imageshack.us/img91/9672/zxdsl831aiieditedku4.th.jpg
After opening in IE delete .th for blowup picture.