San,
Unfortunately in the Gen 1 Digital it is not available. If you want to block the caller id all together, you can try using the trunkiddelivery setup in the pstntg. The thought here is that if the origination device is not a quintum, it will not be sending a trunk id, and if set on your quintum to send the trunk id out as ani, since there is no trunk id, none will be sent out.
MikeM
mike_voip@hotmail.com