I am considering purchasing a Fritzbox Fon 7140.
As I will, initially at least, be using a cable modem, this wil mean I
lose an ethernet socket. Hence the preference over the 7050.

I have checked out the manuals for the
Fritzbox Fon,
Fritzbox Fon 7050,
Fritzbox Fon 7140.
In the 100+ pages of each of the pdf manuals
I can see no mention of Speed dials or callthrough, even though they
are listed in the specs.
I feel sure that speed dials will be easy to set up but what about
calthrough? I have seen various postings referring to this but nowhere
have I seen the methodology behind it. Can anyone point to a place
where there is callthrough set up information

Further, I can see no detailed information, re dialling rules, though
I assume that this is easy to do so, possibly, does not require any
detailed documentation.
Remove 'no_spam_' from email address.