T. Shaw
2006-Jun-29 13:26 UTC
[Asterisk-Users] need help troubleshooting clipping and garbled VOIP calls
Hello all, I have a problem with call quality with my Asterisk setup. I'm doing VOIP only so far, but have a zaptel TDM400P in the box not being used. The problem i'm having is that when calls are placed, connected, and the far-end is reporting that they are experiencing clipping, choppy, and garbled voice conversations. So bad that we have to resort to using our cell phones. This entire setup is still being built, but any phone attached is experiencing this. Call volume is almost nil (under 20 total incoming calls a day). This is a small business setup. The server is used exclusively for Asterisk, so it isn't a fileserver, or anything else. The setup is as such: ipphone <--->cisco 2900XL switch <----> Cisco 2621 router <---> dsl modem <-->DSL <---> VOIPprovider I've configured the switch and the router to set priority and qos to prioritize voice traffic above data. Funny thing is, there is not data REALLY hitting the network. I have setup 2 vlans, data vlan, and voice vlan. There are two work stations on the network, and neither is being used to hit the internet heavily (office is still being setup). Any pointers or suggestions anyone have for me as to were to look for this poor quality? It seems only the Far-end (called party), is hearing this and not the calling party. I haven't tried switching out the phones because we only have 1 type, and any of the phones i used exhibit these problems. I will try softphones to see if it is truly a "networking" issue or Phone issue. Is anyone using a cisco 2900 switch or router and care to provide config samples of their COS/QOS setup? Thanks! Terrelle Shaw
James Hawks
2006-Jun-29 13:39 UTC
[Asterisk-Users] need help troubleshooting clipping and garbledVOIP calls
Sounds like a QoS issue with your DSL provider. If you go to http://www.bandwidth.com/tools/voipTest it might give you some insight. James Hawks -----Original Message----- From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-bounces@lists.digium.com] On Behalf Of T. Shaw Sent: Thursday, June 29, 2006 1:27 PM To: asterisk-users@lists.digium.com Subject: [Asterisk-Users] need help troubleshooting clipping and garbledVOIP calls Hello all, I have a problem with call quality with my Asterisk setup. I'm doing VOIP only so far, but have a zaptel TDM400P in the box not being used. The problem i'm having is that when calls are placed, connected, and the far-end is reporting that they are experiencing clipping, choppy, and garbled voice conversations. So bad that we have to resort to using our cell phones. This entire setup is still being built, but any phone attached is experiencing this. Call volume is almost nil (under 20 total incoming calls a day). This is a small business setup. The server is used exclusively for Asterisk, so it isn't a fileserver, or anything else. The setup is as such: ipphone <--->cisco 2900XL switch <----> Cisco 2621 router <---> dsl modem <-->DSL <---> VOIPprovider I've configured the switch and the router to set priority and qos to prioritize voice traffic above data. Funny thing is, there is not data REALLY hitting the network. I have setup 2 vlans, data vlan, and voice vlan. There are two work stations on the network, and neither is being used to hit the internet heavily (office is still being setup). Any pointers or suggestions anyone have for me as to were to look for this poor quality? It seems only the Far-end (called party), is hearing this and not the calling party. I haven't tried switching out the phones because we only have 1 type, and any of the phones i used exhibit these problems. I will try softphones to see if it is truly a "networking" issue or Phone issue. Is anyone using a cisco 2900 switch or router and care to provide config samples of their COS/QOS setup? Thanks! Terrelle Shaw _______________________________________________ --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
Rich Adamson
2006-Jun-29 13:39 UTC
[Asterisk-Users] need help troubleshooting clipping and garbled VOIP calls
T. Shaw wrote:> Hello all, > I have a problem with call quality with my Asterisk setup. I'm doing > VOIP only so far, but have a zaptel TDM400P in the box not being used. > The problem i'm having is that when calls are placed, connected, and the > far-end is reporting that they are experiencing clipping, choppy, and > garbled voice conversations. So bad that we have to resort to using our > cell phones. This entire setup is still being built, but any phone > attached is experiencing this. Call volume is almost nil (under 20 total > incoming calls a day). This is a small business setup. The server is > used exclusively for Asterisk, so it isn't a fileserver, or anything else. > > The setup is as such: > > ipphone <--->cisco 2900XL switch <----> Cisco 2621 router <---> dsl > modem <-->DSL <---> VOIPprovider > > I've configured the switch and the router to set priority and qos to > prioritize voice traffic above data. > Funny thing is, there is not data REALLY hitting the network. I have > setup 2 vlans, data vlan, and voice vlan. There are two work stations on > the network, and neither is being used to hit the internet heavily > (office is still being setup). > > Any pointers or suggestions anyone have for me as to were to look for > this poor quality? > It seems only the Far-end (called party), is hearing this and not the > calling party. > > I haven't tried switching out the phones because we only have 1 type, > and any of the phones i used exhibit these problems. I will try > softphones to see if it is truly a "networking" issue or Phone issue. > > Is anyone using a cisco 2900 switch or router and care to provide config > samples of their COS/QOS setup?Highly unlikely the ipphones or switch have anything to do with the problem. Most likely cause is the dsl "upload" speed (which is usually substantially slower then download speed). Just as an FYI... the QoS settings in any Cisco product (including the 2900 switch) do not actually kick in "until" a switch port becomes congested. So if your switch ports are running at only 10 megabits, you'd have to be moving data (including voice) at that rate before QoS begins to give priority to voice packets. If your voip provider supports a low bit-rate codec, you might consider using something like g729 to see if that impacts the problem. If it does improve it, then either your dsl connection is the problem (to slow), or, your dsl provider's data network is less then adequate to move the voice packets through in a reliable way. There are several internet sites that you can use to test your bandwidth if you want to try those. One is dslreports.com, but there are others. Goggle should give you plenty to work with.
Thomas Kenyon
2006-Jun-30 01:56 UTC
[Asterisk-Users] need help troubleshooting clipping and garbled VOIP calls
T. Shaw wrote:> > Hello all, > > I have a problem with call quality with my Asterisk setup. I'm doing > > VOIP only so far, but have a zaptel TDM400P in the box not being used. > > The problem i'm having is that when calls are placed, connected, and > > the far-end is reporting that they are experiencing clipping, choppy, > > and garbled voice conversations. So bad that we have to resort to > > using our cell phones. This entire setup is still being built, but any > > phone attached is experiencing this. Call volume is almost nil (under > > 20 total incoming calls a day). This is a small business setup. The > > server is used exclusively for Asterisk, so it isn't a fileserver, or > > anything else. > > > > The setup is as such: > > > > ipphone <--->cisco 2900XL switch <----> Cisco 2621 router <---> dsl > > modem <-->DSL <---> VOIPprovider > > > > I've configured the switch and the router to set priority and qos to > > prioritize voice traffic above data. > > Funny thing is, there is not data REALLY hitting the network. I have > > setup 2 vlans, data vlan, and voice vlan. There are two work stations > > on the network, and neither is being used to hit the internet heavily > > (office is still being setup). > > > > Any pointers or suggestions anyone have for me as to were to look for > > this poor quality? > > It seems only the Far-end (called party), is hearing this and not the > > calling party. > > > > I haven't tried switching out the phones because we only have 1 type, > > and any of the phones i used exhibit these problems. I will try > > softphones to see if it is truly a "networking" issue or Phone issue. > > > > Is anyone using a cisco 2900 switch or router and care to provide > > config samples of their COS/QOS setup? > > > > Thanks! > > > > Terrelle Shaw > > >I've got a similar setup (which does have a TDM card and voip incoming and outgoing), for some reason an IAX provider (which provides most of our calls incoming and outgoing) has this problem, whereas a different SIP one doesn't seem to. I have checked my traffic shaping script, and everything seems fine, the same provider works flawlesly from home, with a simliar setup (only without a timing source and a cable modem). I'd be very interested to see what you find out.>