U0040 [1] filed a orphan request for udptunnel [2]:

The URL for the download 404s and has done so since at least 2017. There is a new URL available but the maintainer seems inactive and has not responded to my email.

[1] https://aur.archlinux.org/account/U0040/ [2] https://aur.archlinux.org/pkgbase/udptunnel/