Sean Kennedy
2006-Oct-07 15:30 UTC
[asterisk-users] disabling hardware echo can on tdm2400p
Hey list, Short version: I have a need to disable the hardware can on the tdm24xxp I have. I figure it's something in zconfig.h in the zaptel directory, but I'll be damned if I can figure it out. Long version: I have a tdm2403e card which is experiencing an odd problem; When several lines are in use, there is a "bleeding" of lines. My users call it the 'ghost'. Regardless, they can hear other people's conversation on different lines. I've been told this has to do with the hardware echo can I have on there, and that I should disable it if I continue having problems. So that's where I stand. Answers and opinions welcome. Sean
Eric "ManxPower" Wieling
2006-Oct-08 13:18 UTC
[asterisk-users] disabling hardware echo can on tdm2400p
Sean Kennedy wrote:> Hey list, > > Short version: > I have a need to disable the hardware can on the tdm24xxp I have. I > figure it's something in zconfig.h in the zaptel directory, but I'll be > damned if I can figure it out. > > Long version: > I have a tdm2403e card which is experiencing an odd problem; When > several lines are in use, there is a "bleeding" of lines. My users call > it the 'ghost'. Regardless, they can hear other people's conversation > on different lines. I've been told this has to do with the hardware > echo can I have on there, and that I should disable it if I continue > having problems. So that's where I stand. > > Answers and opinions welcome.Crosstalk is not an Echo Cancel issue. It is usually caused by a wiring issue. Search the archives or look at the Zaptel README for the module option to disable the echo canceler.
Hi. I don't believe this course of action will fix your issue. It sounds like crosstalk, where stray signals from one pair are transmitted onto another. My standard voice quality troubleshooting fix is as follows. 1. If the zaptel module is ancient, install the new release. 2. Stop asterisk and run 'fxotune -I 5'. This takes a while, 3-4 minutes per line. 3. Add 'fxotune -s' to /etc/init.d/asterisk 4. Ask the Telco for the number to a milliwatt test line and use the "correct" procedure to set the incoming gain in zaptel.conf. 5. Loop two lines and use the "correct" procedure to set the outgoing gain in zaptel.conf. 6. Reset all the echo cancelling and training settings to default. Fxotune does some magic that matches the internal settings of the zaptel card to the lines. Setting the gain properly in the zaptel.conf puts the incoming signal into the optimal range of the echo filters. Resetting the echocanceler and training settings back to default pulls everything back to a known value, which usually works well. This has fixed it for me every time except once. In the case of the "once", a cheap phone cable (flat, not twisted) was run 35 feet around the edges of the room, under space heaters, from the NID to the closet, butt-spliced and hooked to the 66block, and then to the PBX. Replacing this cable with a category 5 cable run under the house (I didn't have any Cat3) fixed it. Ejay Hire -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of Sean Kennedy Sent: Saturday, October 07, 2006 5:31 PM To: Asterisk Users Mailing List - Non-Commercial Discussion Subject: [asterisk-users] disabling hardware echo can on tdm2400p Hey list, Short version: I have a need to disable the hardware can on the tdm24xxp I have. I figure it's something in zconfig.h in the zaptel directory, but I'll be damned if I can figure it out. Long version: I have a tdm2403e card which is experiencing an odd problem; When several lines are in use, there is a "bleeding" of lines. My users call it the 'ghost'. Regardless, they can hear other people's conversation on different lines. I've been told this has to do with the hardware echo can I have on there, and that I should disable it if I continue having problems. So that's where I stand. Answers and opinions welcome. Sean _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users