The new Wi-Tribe CPE WiMAX modem from greenpacket model EX-230 is more secured and powerfull with high gain antenna using MIMO technology. By default the username and the password for the Graphical User Interface (GUI) is admin likewise for the telnet is "user" both are lowercase.
If in the case you can not access the Graphical User Interface (GUI) or the Command Line Interface (CLI) using telnet likewise via putty. Try to hard reset by using a small pin by inserting onto the pin hole at the back of the WiMAX CPE modem then just used the same Username and Password as mention above. Feel free to comment if you have any question.