1. Can 8841 register to CUCM 8.6..2. Is there any additional patches which is required for this3. Documentation / link for the same

I am trying to migrate a customer from CUCM 4.3 to CUCM 10.5/ 10.6. The customer has exisitng phones ( 7906,7910,7911,7912,7940,7941,7942,7960,7962,7970). Can someone point out which phones can be reused. I tried visiting the website but it was a bit...