@Stewart1, @PitzKey , thanks a lot for your suggestions and comments.
It appears that CID matching on the inbound route is case sensitive! My provider sends it as ‘anonymous’! All along I have been trying out with ANONYMOUS and Anonymous and both of course failed. A trap for the new players, I guess 
@Stewart1, can you please let me know how you do the incoming CID check against the Phonebook and determine whether there is a match or not?