Dct4 Link

Older DCT3 phones were wide open. With DCT4, Nokia locked down flashing. You needed special boxes (like JAF, UFS, or Griffin) and original MCU+PPM files.

Here’s a short, interesting blog-style post about (Digital Cordless Technology, 4th generation — often associated with DECT, but “DCT4” is also a known Nokia phone motherboard generation). Older DCT3 phones were wide open