Date: Wed, 7 Nov 2007 16:47:47 +0100 From: "Michael Iedema" <michael@askozia.com> To: freebsd-isdn@freebsd.org Subject: echo cancellation / suppression in chan_capi & isdn4bsd by HPS Message-ID: <d3dd0e360711070747xa3a77faw1c7cb8656fc796da@mail.gmail.com>
next in thread | raw e-mail | index | archive | help
Greetings everyone, I'm trying to understand what options are available to me regarding echo cancellation and suppression in chan_capi and isdn4bsd from HPS (http://www.turbocat.net/~hselasky/isdn4bsd/). Great software, just trying to understand it a bit more thoroughly. In the chan_capi code, I see references to: - echo cancellation in hardware - echo cancellation in software - echo suppression in software I understand the chan_capi options to mean: - echocancel - activates hardware echo cancellation if it is available or software echo cancellation in the i4b driver if it is not. - echosquelch - activates some "light" echo cancellation in the chan_capi code itself - echocancelold - must be activated for older cards not supporting the new echo cancellation method - echotail - echo can tap count Here's what I'm still not clear on: - What do the g164, g165 and force options cause on the "echocancel" line? - Are the echocancel/echosquelch options smart enough to only be activated if the "better" of the two is already activated? - Is there a way to tell if a card needs "echocancelold" to be set? - What is the value range for "echotail"? (32, 64, 128, 256?) Thanks in advance for any feedback on this. -Michael I.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?d3dd0e360711070747xa3a77faw1c7cb8656fc796da>