I work for a call center and I work with a 7942 Cisco IP Phone. I’m always impressed by the quality of the phone. The feature that I love a lot would be the speaker phone. I thought it would be a perfect addition to my room and so I searched for it online and see where I can get a good deal. I was lucky enough to get multiple phones for a cheap price on Craigslist. At that time, my dad was telling me that you can convert SCCP to SIP only if you are a Cisco Certified so I had to do some digging online. I found a lot of tutorials on how to do it and sites where you can download firmwares and upgrade it via TFTP.
I have read a lot of tutorials and all of them seemed to vary. I followed one after another until I got the hang of it. (trial and error, I know it is not good especially when messing with firmwares. I do it a lot..)