I know that it is not an ISP issue. It is an RTI software issue. The software adds the 80 by default in the command string that you can not see or change. Read the 2nd post by Springs carefully. If you are using port 8003, then you will need to add :03 at then end of the static IP address on your command sets. Last I checked you still can not change this. So, if you decide to use any port other than the prefix of 80 it will need to be changed. Just do a test of using 8081 on a camera.