After the instance starts running, one has 3 choices to connect to the Ubuntu Desktop: browser, VNC client or RDP client.

For browser connection, simply open a browser page at the instance's public IP address (e.g., "http://54.145.197.17 " or "https://54.145.197.17 ", where "54.145.197.17" is the instance's public IP address). It will ask for a password, which is the same as VNC password and is initially set as the EC2 instance ID (e.g., i-0548053a20dc74bb2). After entering the correct password you will automatically log into the Ubuntu desktop session as the default "ubuntu" user.

For VNC connections, use your favorite VNC client software (e.g., tigerVNC, tightVNC, realVNC) and connect to the instance public IP address at port 5900. The initial VNC password is the EC2 instance ID (e.g., i-0548053a20dc74bb2). After successful connection, you will automatically log into the Ubuntu desktop session as the default "ubuntu" user.

For RDP connections, use your favorite RDP client software (e.g., Windows Remote Desktop Connection, or Linux rdesktop), and connect to the instance public IP address. You will be asked to enter the user name and password before entering a Ubuntu desktop session.

If you like to configure firewall manually instead of using the default one, please open the following TCP ports for incoming traffic: 22, 80, 443, 3389, 5900. For more usage tips, refer to the support forum, https://netspectrum.com/forum/viewforum.php?f=3 

Please note: 1) Browser connection is using the same VNC protocol as VNC client connection, and at any time only one VNC session can be active. 2) Don't log in the same user from both VNC session and RDP session. 3) Default "ubuntu" user is automatically logged in over VNC sessions. 4) RDP connection supports multiple users with multiple concurrent sessions. Please create additional users for RDP connections. 5) The initial password for the default user, "ubuntu", is the EC2 instance ID.