Friends, you should definitely take a look at the Yeahlink website if you have an IP phone from Yealink. I found the instruction manual there, and it's just great. All information is presented very clearly and legibly, and most importantly, it can be downloaded for free. Also there is a huge number of different variants and models of phones, so, believe me, it will make your life much easier. Trust me, without this site I would definitely be stumped!