The question here is whether a general forwarding of all calls without call acceptance or a forwarding during the call is meant.
In my opinion, the former has nothing to do with this handset, which needs a base station for such functions. Call forwarding is normally set on the base station or in the web interface of the telephone provider (Swisscom, Sunrise etc).
Forwarding during an ongoing call is only possible internally to another handset on the same base station.