P-660HN-T1H firmware build with IPv6 support, according to the title, supplied as a 5.18 MB RAR. The T1H suffix marks a variant of the P-660HN modem, so the image should only go onto that exact model. Technicians apply such firmware to add features, fix bugs or recover a device stuck at boot, using the web upload page or bootloader recovery. Read the label on the unit and keep a copy of the current settings first, since changing firmware usually resets the configuration.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @afsbiosfree. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →