[asterisk-users] Change the caller's phone number

[Eyal]

Hi,
I have a system that receives calls from clients and directs them to an
external phone,
before I pass on the client I change the client's phone number to a
number that I choose, so that The call recipient knew the call came from
our system.
But I have a problem with that, not all phone number change some of the
anonymous calls stay anonymous and the recipient See in the caller ID
display unlisted number.
I use this commend:
Set(CALLERID(all)="722979797" <722979797>)

Is anyone having a similar problem or know what the problem?

Thanks.