We have a strange echo problem. Maybe echo isn't the correct term. When we make a call f/ a SIP phone (we have several 7960's, some 3coms, and I've even tried a softphone, all on the same 100BaseTX network) to the pstn, if the person I'm calling has a PRI or channelized T1 f/ Bell, then the sound is perfect, couldn't be better. If I make a call to a person with a plain POTS line, I hear everything I say in my earpiece about 1/4 second after I say it. It's very irritating. We have tried 2 different * boxes, using 2 different T1/PRI cards f/ digium. After calling digium about it, we set echotraining to 800 in zapata.conf. It got better but was still there, if I turn the volume down on the phone, it does "almost" go away, but it's still detectable. No where near as clear as calling a person that has a PRI or channelized T1 for phone service. The POTS persons we call that we do have the echo issue with all say the call sounds perfecto to them. Am I missing something obvious? W. Kevin Hunt CCIE #11841
> We have a strange echo problem. Maybe echo isn't the correct term. > When we make a call f/ a SIP phone (we have several 7960's, some 3coms, > and I've even tried a softphone, all on the same 100BaseTX network) to > the pstn, if the person I'm calling has a PRI or channelized T1 f/ Bell, > then the sound is perfect, couldn't be better. > If I make a call to a person with a plain POTS line, I hear everything I > say in my earpiece about 1/4 second after I say it. It's very > irritating. We have tried 2 different * boxes, using 2 different > T1/PRI cards f/ digium. > > After calling digium about it, we set echotraining to 800 in > zapata.conf. It got better but was still there, if I turn the volume > down on the phone, it does "almost" go away, but it's still detectable. > No where near as clear as calling a person that has a PRI or channelized > T1 for phone service. The POTS persons we call that we do have the echo > issue with > all say the call sounds perfecto to them. > > Am I missing something obvious?No, your not missing anything specifically. There seems to be a fair number of people with those same type of echo problems, which are the most difficult things to diagnose. There's no easy way to determine whether this is an * or pstn problem, so most of the previous efforts have been focused on ruling out what is not the problem. It would help all of us better understand the issues if at least some additional data were provided, however. Such things as cvs version, significant portions of 'zap show channel...' with the echo can data, and anything else that seems to narrow the focus. In most cases, turning volumes/gains down is a method to bypass the problem, not solve the root cause. (Certainly not true in all cases.) Personal opinion (based only on the various words posted to this list) is there still is an echo can issue floating in * that none of us have documented with sufficient data that would guide a developer towards the root cause. If you easily recreate the problem, that would go a long ways towards gathering qualifying data. Rich
I can consistently recreate the problem and will be happy to give a developer or two a sip or iax account on one of my test asterisk boxes to play with. It would take me a week or so to get a new box up w/ a t1 card that we are constantly messing with. W. Kevin Hunt CCIE #11841 MCSE, Linux+ SME www.huntbrothers.com Trimmed for electron conservation.... -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Rich Adamson Sent: Friday, July 09, 2004 9:36 AM To: asterisk-users@lists.digium.com Subject: Re: [Asterisk-Users] strange echo problem> We have a strange echo problem. Maybe echo isn't the correct term. > When we make a call f/ a SIP phone (we have several 7960's, somePersonal opinion (based only on the various words posted to this list) is there still is an echo can issue floating in * that none of us have documented with sufficient data that would guide a developer towards the root cause. If you easily recreate the problem, that would go a long ways towards gathering qualifying data. Rich
> We have a strange echo problem. Maybe echo isn't the correct term. > When we make a call f/ a SIP phone (we have several 7960's, some > 3coms, and I've even tried a softphone, all on the same 100BaseTX > network) to the pstn, if the person I'm calling has a PRI or > channelized T1 f/ Bell, then the sound is perfect, couldn't be better. > If I make a call to a person with a plain POTS line, I hear everything > I say in my earpiece about 1/4 second after I say it. It's very > irritating. We have tried 2 different * boxes, using 2 different > T1/PRI cards f/ digium. > > After calling digium about it, we set echotraining to 800 in > zapata.conf. It got better but was still there, if I turn the volume > down on the phone, it does "almost" go away, but it's still > detectable. No where near as clear as calling a person that has a PRI > or channelized T1 for phone service. The POTS persons we call that we > do have the echo issue with all say the call sounds perfecto to them. > > Am I missing something obvious?We experience the exact same issue, and like Rich said in a subsequent post, I'm thinking there's a gremlin hiding somewhere in the * code. Everyone said you shouldn't have to even use echo canceling on a T1 PRI, but we do or we get serious complaints, instead of consistent minor complaints. FWIW, it still was around in the 6/29 CVS and we just updated again last night. For us the echo is a slight faint echo now that we implemented the echotraining=800, but it's still there. We haven't touched TX/RX gain. We can also give anyone access and a SIP account if that would be helpful. Best regards, Ryan Thrash
Please let me know if you find a solution, I'll do the same. I received this from the FISPA list, and have ordered a 6400R which should arrive Friday for testing. *** begin paste *** If you are using asterisk and digium cards, they are very sensitive to CPU/IRQ speed. We had this issue until we moved the install to a high end Proliant with a nice bus. IOW a P4 2.4GHZ new generic machine/motherboard was not having bus throughput as good as a Proliant Xeon 500/1M Cache. Our far end echo issue went away when we moved to a production class server. I'm not a programmer but P4's seem to generate way more inpterrupts than P3's and this means other items on the bus get their turn last. One other note: Stay away from AMD processors with Asterisk too. Our experience shows they perform dismally. Slower Xeons with big cache work better for us and our production box has perfect audio on both ends now. You can pick up a 6400R Compaq for about $700 now. Awesome machine. We're running ours on a DL-380 with RAID 5 and it's performing perfectly. *** end paste *** W. Kevin Hunt CCIE #11841 MCSE, Linux+ SME www.huntbrothers.com -----Original Message----- On Behalf Of Ryan Thrash Subject: Re: [Asterisk-Users] strange echo problem> We have a strange echo problem. Maybe echo isn't the correct term. > When we make a call f/ a SIP phone (we have several 7960's, some > 3coms, and I've even tried a softphone, all on the same 100BaseTX > network) to the pstn, if the person I'm calling has a PRI or > channelized T1 f/ Bell, then the sound is perfect, couldn't be better. > If I make a call to a person with a plain POTS line, I hear everything> I say in my earpiece about 1/4 second after I say it. It's very > irritating. We have tried 2 different * boxes, using 2 different > T1/PRI cards f/ digium.For us the echo is a slight faint echo now that we implemented the echotraining=800, but it's still there. We haven't touched TX/RX gain. We can also give anyone access and a SIP account if that would be helpful. Best regards, Ryan Thrash