For the VoIP connecting to the PSTN, echo with the voice communication has been a problem hard to solve and inevitable . Asterisk has a range of software-based Open Source echo cancellation routines that are moderately effective in eliminating the echo. However, there are cases in which these algorithms are not effective.
To solve this problem, ATCOM offers a line of DSP-based echo cancellation modules for all the digital (T1/E1/J1) cards with the EC series modules.
Work with AXE4DL
128 channels G.168–2002 echo cancellation in hardware
1024 taps/128 ms tail per channel on all channel densities
DTMF decoding and tone recognition
Voice quality enhancement: music protection, acoustic echo control, and adaptive noise reduction
Does not increase the physical size of the card, and no additional slot is required