FRITZ!Box routers always expect to have a editable CardDAV phonebook to sync with. If one tries to sync directly with EPVPN carddav phonebooks, FRITZ!Box issues an “error code 22”. Most propably, this is due to EPVPN CardDAV being read-only.

Therefore one can sync EPVPN to a private, editable CardDAV provider, such as a Nextcloud, Owncloud or similar server. As Next-/Owncloud are not able to sync with other CardDAV servers themselves, one may use a sync tool for this. In this example we will use pimutils/vdirsyncer to sync with a Nextcloud CardDAV in order to make the synced phonebook available to FRITZ!Box.

(to be continued…)