I understand. I could not find anything about from Junipers side other than what you see for th edescription. SO it took a while to find it, but I found a website which was discussing some kind of modules that had the lED lights that seemed to change depending on the power into the power supply, and they had a list of abbr. with OTP among others. I should have posted the link but I will look it up later and add it so others can see what that other company is talking about. The MX104 seems to be a nice MX router but the documentation is still not as much as can be found on other devices. I don't know if they even know what it means:) I am just playing. Got to have some fun with them for being so skimpy on details like that. Maybe one of the hardware docs on the MX 104 may have that info.