Translations:Brother networked printer/166/en
From Gentoo Wiki
Brother also seems to offer a newer proprietary brscan5 driver (no Gentoo package known yet, bug #833603). At least for some scanners, brscan5 seems to provide additional specific options (e.g. "auto deskew"). Obviously, brscan5 optionally uses more advanced protocol, still on same TCP port 54921, at least for scanners supporting this. However, details (e.g. differences in feature set, device backward compatibility) are unknown.