Thanks Mr. Paolo,
I can;t open your link.
We paid the E1 link ( 30 Channel ) monthly charge for whole channels so if I used 12 channel or 30 channel, I should pay the same amount.
If I use VWIC port, that means I need a new E1 link while my idea to use the avaliable channels in the used E1 link. Do you have other solution to use the same E1 link for data and voice?