Question: how to change username and password in bsnl broadband modem?
Answer: STEP 1: Log into BSNL broadband modem. By default BSNL modem has IP address of 192.168.1.1, you can log into your modem by typing this into your browser address bar: 192.168.1.1. ... 
STEP 2: Change password of your BSNL broadband modem from its configuration page.