the telephone has CID function
set prepaid card in it
save telephone fees
adjust volume,hot line, much functions

BY-2000 is a kind of IP telephone, it has ordinary telephone functions, but also can store prepaid card information.

set the access number , passwords of prepaid card in it, when you make call, the telephone can detect number you dial and choose whether deduct fees from card or telephone.

no any extra fees for users.