I have a Hikvision DS-7608NI-I2-8P in the loft, power in the loft.
I also have 3 x DS-2CD2347G2-LSU/SL.
When it was installed I had a CAT5 cable run down to the front door if I was going to add another camera facing out from the above the front door.
I would like, or thought I did, a doorbell...