How would I know incoming call is forwarded(divert) or not?

[Roosh]

How would I know incoming call is forwarded(divert) or not?

[Ařpît]

To check whether the divert is set up, dial *#21#.
...
To divert calls, dial *21*, followed by either:

the extension number, followed by #.the site location code and extension number, followed by #.9 then the telephone number, followed by #.