I have been battling echo since we installed a new system at one of our clients. I am using a single span digium card. I believe this is the first time someone has setup a PRI in this area (its way out in the middle of nowhere). We get slight echo on all calls, and when calling some numbers (long distance calls but still in the local area), we get very loud echo. The person calling out can hear their own voice at the same volume about a half second after they speak. Its been getting annoying and I have tweaked everything I can, and even tried diferent echo cans in zaptel. I have talked to the telco (Bellsouth) which does both local and long distance, and they couldn't help me. They can fix the long distance echo, but they seem to fix it only on a per number basis (I call with one number, and they fix it, but then I call with another number, and they fix that, but it never actually fixes ALL the echo for long distance). I am looking into hardware echo cancelers, but I haven't found a place to get one. Would switching to Sangoma cards help fix my issues? I know Digium cards have issues on some servers/motherboards, and yet I haven't heard of any issues with Sangoma cards. If someone has had issues then I would like to hear them. I know I can find some hardware echo can's on ebay and wire it up, but I would like to have a better product that comes as a single span T1. Thanks, Tad
On Tuesday 04 October 2005 10:37, Tad Heckaman wrote:> the middle of nowhere). We get slight echo on all calls, and when > calling some numbers (long distance calls but still in the local > area), we get very loud echo. The person calling out can hear their > own voice at the same volume about a half second after they speak. ItsWe get that with our Bell Canada PRI only on certain (local) exchanges. I'm not exactly sure what is causing it but it's been a problem since we installed the PRI.> Would switching to Sangoma cards help fix my issues? I know Digium > cards have issues on some servers/motherboards, and yet I haven't > heard of any issues with Sangoma cards. If someone has had issues then > I would like to hear them.I doubt it, the echo can seems to be working just fine, but in your case (and mine) it seems like it must be getting disabled. I must admit it's been a while since I've dove into this problem, but if you execute dmesg -c on the asterisk box, make a call that will echo, and execute dmesg -c again, is there any mention of "echo canceller disabled on channel 5" in the resultant output? -A.
I know that many don't like to say it on this message board out of political correctness but in all honesty, Digium cards do not seem to have a very good reputation. They are slowly getting better. I cannot comment on the Digital cards but everyone knows of the problems with interrupts and the TDM400P card. Digium calls this imcompatibilities with certain boards and configurations but the simple fact is that the TDM400p cards do not handle interrupts very well and therefore they tend to have these interrupt and compatibility issues. Sangoma seems to understand this better. They have been making interface cards a LOT longer than Digum so I think they are better at this. Just my opinion.> -----Original Message----- > From: Tad Heckaman [mailto:douglash@gmail.com] > Sent: Tuesday, October 04, 2005 7:38 AM > To: asterisk-users@lists.digium.com > Subject: [Asterisk-Users] Echo Canceling > > I have been battling echo since we installed a new system at > one of our clients. I am using a single span digium card. I > believe this is the first time someone has setup a PRI in > this area (its way out in the middle of nowhere). We get > slight echo on all calls, and when calling some numbers (long > distance calls but still in the local area), we get very loud > echo. The person calling out can hear their own voice at the > same volume about a half second after they speak. Its been > getting annoying and I have tweaked everything I can, and > even tried diferent echo cans in zaptel. I have talked to the telco > (Bellsouth) which does both local and long distance, and they > couldn't help me. They can fix the long distance echo, but > they seem to fix it only on a per number basis (I call with > one number, and they fix it, but then I call with another > number, and they fix that, but it never actually fixes ALL > the echo for long distance). I am looking into hardware echo > cancelers, but I haven't found a place to get one. > > Would switching to Sangoma cards help fix my issues? I know > Digium cards have issues on some servers/motherboards, and > yet I haven't heard of any issues with Sangoma cards. If > someone has had issues then I would like to hear them. > > I know I can find some hardware echo can's on ebay and wire > it up, but I would like to have a better product that comes > as a single span T1. > > Thanks, > Tad > >
> -----Original Message----- > From: asterisk-users-bounces@lists.digium.com > [mailto:asterisk-users-bounces@lists.digium.com]On Behalf Of Rich > Adamson > Sent: Wednesday, October 05, 2005 9:23 AM > To: Asterisk Users Mailing List - Non-Commercial Discussion > Subject: Re: [Asterisk-Users] Echo Canceling > >{clip}> > Identifying why a echo cancel tone is occurring on a normal voice call > is reasonable, but why would a _local_ echo canceller be needed on a > four-wire full-duplex digital link? > > If the end-to-end call is digital all the way, there really isn't a need > for it. So, isn't the issue one of who has responsibility for inserting > the echo canceller when a 4-wire to 2-wire hybrid is involved? (Obviously, > its not the originating site since one would have no idea what the > destination site is doing.) Or, is there an assumption going on that says > an echo canceller is always needed on all pstn calls > regardless of whether is doing anything or not? >Certainly this is correct if you're only considering the transport network, however it's also possible there are acoustic echos occuring inside the remote parties handset (ie. cheap handsets) or, if they've got you on a speakerphone, acoustic echos from the room itself. We do PRI-IAX-PRI calls between Norstar PBXs (digital path from handset to handset) and were still forced to install hardware echo cancellers facing towards each PBX to supress the acoustic echos introduced when a user went on to handsfree mode. If you consider the enormous number of trashy sets out in the world it becomes more reasonable to simply provision your own echo cancellation system facing the PSTN just incase. Kris Boutilier Information Services Coordinator Sunshine Coast Regional District