It is a device capturing and controling all the signals, which are being created by the whole system, especially the made and received phone call signals. The device is mostly used for connecting regular phone system with the Internet and backwards.
Digium Wildcard TE407P card has a built-in hardware echo cancellation, based on a powerful digital signal processor. Board supports E1, T1 and J1 interfaces, which can be configured for each interface or the entire board as a whole.