What are credentials needed for resetting BSNL FTTH ONT device?

[neonbulb]

My BSNL FTTH ONT device is OptiLink OP-GONT 90211VW. I changed some settings of this device, but now its unable to connect the its own portal -192.168.10.1 . I'm now planning to reset this device. Could anyone say what are the credentials needed to re-enter after reset? I've the screenshots of the WAN settings page which include username, password, VLAN ID, etc. Are these the only details needed? I remember there were some details in Voice page, but I didn't took the screenshot of it.