Hi, I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig Memory, Dell 2650). Telco - PRI - Asterisk - T1 - PBX I am getting an occasional noticeable echo on some of the phone lines (random inbound and outbound). Everyone I ask keeps telling me that I can't be having echo since I am on a PRI, which is a digital circuit. Ok, so I can't be having echo, but I am! Does anyone have any ideas of what might be causing the echo in this situation? Thanks, Dave
I think I saw a reference to a similar problem and it regarded IRQ issues on the machine in question. IF there was IRQ sharing, cagey things happened. But if the T1 card had a static IRQ, it resolved the issue. Does your T1 card have a dedicated IRQ? I am sure someone will be able to explain further and possibly give you some validation on your Mobo too? Thanks, Wiley -----Original Message----- From: David Goldfein [mailto:dave@swtravel.com] Sent: Monday, July 19, 2004 5:13 PM To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Echo on a PRI Hi, I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig Memory, Dell 2650). Telco - PRI - Asterisk - T1 - PBX I am getting an occasional noticeable echo on some of the phone lines (random inbound and outbound). Everyone I ask keeps telling me that I can't be having echo since I am on a PRI, which is a digital circuit. Ok, so I can't be having echo, but I am! Does anyone have any ideas of what might be causing the echo in this situation? Thanks, Dave _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Might as well come join the * SIG echo-echo_list@secondphone.com bare your sole there ...
> I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I > can't be having echo since I am on a PRI, which is a digital circuit. > Ok, so I can't be having echo, but I am! > Does anyone have any ideas of what might be > causing the echo in this situation?There are many far more knowledgeable than I about echo but in the interim I will contribute from my limited understanding. While echo will not be generated at the interface between your Asterisk server and the PRI trunk, echo still can be generated elsewhere in the network (i.e. at the other end of the call where your "digital" call is converted into analog to interface with the two copper wires running to the POTS phone). Normally end-to-end latency for local calls is so short that the echo appears (if it appears at all) as reverb rather than echo. The problem is that if you are running VoIP calls through your Asterisk box you can introduce enough latency so that the echo already present in the system becomes noticeable. Hence the need to enable echo cancelling. Read the wiki and play with the parameters and #defines in the echo can code. Good luck! George Pajari netVOICE communications
On Mon, 19 Jul 2004, David Goldfein wrote:> Hi, > I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig > Memory, Dell 2650). > > Telco - PRI - Asterisk - T1 - PBX > > I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I can't > be having echo since I am on a PRI, which is a digital circuit. Ok, so I > can't be having echo, but I am! Does anyone have any ideas of what might be > causing the echo in this situation?If you've got any analogue anywhere in the call patch then echo is a possibility. Specifically 2-wire analogue. So if one or both of your callers are on analogue phones. Its not usually an issue with your sort of setup though because the Zaptel driver has echo cancellation (have you enabled it?) and the overall call delay is small. Steve
On Mon, 2004-07-19 at 19:52, TC wrote:> Might as well come join the * SIG echo-echo_list@secondphone.com > bare your sole there ...This fragmentation helps us how? -- Steven Critchfield <critch@basesys.com>
On Mon, 2004-07-19 at 19:12, David Goldfein wrote:> Hi, > I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig > Memory, Dell 2650). > > Telco - PRI - Asterisk - T1 - PBX > > I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I can't > be having echo since I am on a PRI, which is a digital circuit. Ok, so I > can't be having echo, but I am! Does anyone have any ideas of what might be > causing the echo in this situation?Your PRI and the T1 itself cannot introduce echo on their own. What you may see though is that you are introducing a delay as you traverse the asterisk link. Asterisk will buffer 8 bits per channel from the PRI before it send it down the T1 line to the PBX. This is a new delay that is now added on to the latency your PBX introduces. A guess is that you also get the 2 machines fighting against each other on the echo. I doubt you can turn off echo cancel in the PBX so you should try turning it off in asterisk. It should help reduce some latency in asterisk and let the PBX handle the rest of the echo cancel on it's own. -- Steven Critchfield <critch@basesys.com>
> I recently set up the following in a production system (2.8 GHZ Xeon, > 1 Gig > Memory, Dell 2650). > > Telco - PRI - Asterisk - T1 - PBX > > I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I > can't > be having echo since I am on a PRI, which is a digital circuit. Ok, > so I > can't be having echo, but I am! Does anyone have any ideas of what > might be > causing the echo in this situation?Welcome to the club. ;) You have the same exact problem I've got. The only difference is I'm using dual Xeon 2.4s and a Supermicro SuperWorkstation 7033A-T (X5DAL-TG2 motherboard http://supermicro.com/products/motherboard/Xeon/E7505/X5DAL-TG2.cfm ). Echo training=800 on a recent CVS helped, but did not totally resolve the issue. Best regards, Ryan Thrash
> I recently set up the following in a production system (2.8 GHZ Xeon, > 1 Gig > Memory, Dell 2650). > > Telco - PRI - Asterisk - T1 - PBX > > I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I > can't > be having echo since I am on a PRI, which is a digital circuit. Ok, > so I > can't be having echo, but I am! Does anyone have any ideas of what > might be > causing the echo in this situation?Oops. I need to correct my last post: I don't have the PBX in the mix. My config is dual Xeon 2.4s, 1GB RAM, HW SATA RAID, SuperMicro X5DAL-TG2 motherboard connected to: Telco - PRI (T100P) - Asterisk - SIP Phones (Budgetones 102s/Snom 200) The premise is still the same though: echo present despite our digital PRI that *should* make this impossible. It's usually only echo on our side when calling out as has been discussed here previously ad nauseum with no one being able to really figure out its source. I wish I knew where to really start poking around to try to help get to the bottom of this. Best regards, Ryan Thrash
You can have echo even w/ PRI's, it's just that the echo isn't INTRODUCED at the PRI demarcation point, it is INTRODUCED somewhere along the call path, usually where the 4 wire digital signal to 2 wire analogue signal conversion point exist. We found that moving to a Compaq DL380 or 6400R and compiling in a few extra options (see one of my previous post) totally abolished our echo problem. W. Kevin Hunt CCIE #11841 MCSE, Linux+ SME www.huntbrothers.com -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of Ryan Thrash Sent: Tuesday, July 20, 2004 8:13 AM To: asterisk-users@lists.digium.com Subject: Re: [Asterisk-Users] Echo on a PRI> I recently set up the following in a production system (2.8 GHZ Xeon, > 1 Gig > Memory, Dell 2650). > > Telco - PRI - Asterisk - T1 - PBX > > I am getting an occasional noticeable echo on some of the phone lines > (random inbound and outbound). Everyone I ask keeps telling me that I> can't be having echo since I am on a PRI, which is a digital circuit.> Ok, so I can't be having echo, but I am! Does anyone have any ideas > of what might be causing the echo in this situation?Welcome to the club. ;) You have the same exact problem I've got. The only difference is I'm using dual Xeon 2.4s and a Supermicro SuperWorkstation 7033A-T (X5DAL-TG2 motherboard http://supermicro.com/products/motherboard/Xeon/E7505/X5DAL-TG2.cfm ). Echo training=800 on a recent CVS helped, but did not totally resolve the issue. Best regards, Ryan Thrash _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Thanks Everyone! I appreciate all the feed back. Right now I am using a Digium T400P card and my system, although it is fast, has a slight load, about 15% due to some mysql activity. I know that Digium as a new card the TE410P. Does anyone have any experience in the new card and is the speed difference likely to help with the echo? Also, if I put in a second processor, is that likely to help with the echo? Thanks Again, Dave -----Original Message----- From: asterisk-users-admin@lists.digium.com [mailto:asterisk-users-admin@lists.digium.com] On Behalf Of David Goldfein Sent: Monday, July 19, 2004 5:13 PM To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] Echo on a PRI Hi, I recently set up the following in a production system (2.8 GHZ Xeon, 1 Gig Memory, Dell 2650). Telco - PRI - Asterisk - T1 - PBX I am getting an occasional noticeable echo on some of the phone lines (random inbound and outbound). Everyone I ask keeps telling me that I can't be having echo since I am on a PRI, which is a digital circuit. Ok, so I can't be having echo, but I am! Does anyone have any ideas of what might be causing the echo in this situation? Thanks, Dave _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
On Tue, 2004-07-20 at 13:01, David Goldfein wrote:> Thanks Everyone! > > I appreciate all the feed back. > > Right now I am using a Digium T400P card and my system, although it is fast, > has a slight load, about 15% due to some mysql activity. > > I know that Digium as a new card the TE410P. Does anyone have any > experience in the new card and is the speed difference likely to help with > the echo? > > Also, if I put in a second processor, is that likely to help with the echo?Our only PSTN touching asterisk machine uses a T400P card on a 1200Mhz PIII on a supermicro machine. The majority of our calls are PRI to a T1 into ADIT600 and into an old Dialogic based system. No echo there. Next most calls are redirected from the PRI back to the PRI for connection to some analog phones. Again, no echo. A few calls are passed from PRI to a IAX connection that travels 12 or so hops and land on a cheaply built machine with a T100P card and a Zhone channel bank. Lots of delay, but no echo. All this to say, I would worry about your 15% load on mysql. Treat you machine right by removing the mysql load and see if it fixes your problem. Since you have put mysql with that load on the same machine as your PBX, I would about bet you have IDE drives too. It may well be that your mysql load itself is not much, but the IDE load on top of mysql causes even more delay than is tolerable. -- Steven Critchfield <critch@basesys.com>