I'm struggling to get my VOIP installation to be acceptable. I'm looking for advice on what else I can look for. My system: o Teliax VOIP service, voip-ny1 proxy o RCN Cable Internet Service (3Mbps download, 500kbps upload, 6ms average jitter) o 3.2 GHZ P4 Server (runs asterisk, firewall, other stuff) o server lightly loaded o Linux kernel 2.6.19.2 o Shorewall Firewall software with QOS configured for VOIP P1 o Asterisk 1.4.0 o Sipura SPA-2000 o Grandstream GXP-2000 o IAX connection to teliax Outbound voice quality is many times horrible, to the point where ppl say they cannot hear me. The voice often drops out. Inbound quality seems to cut in and out too. I downloaded the myVoipSpeed VOIP analyzer. It indicates that I have plenty of download and upload bandwidth. I also have good jitter. The tool doeesn't find any packet loss whatsoever. My RCN cable company cannot find anything wrong with my cable modem. No packet loss. I'm supposed to be paying for 10M bit downloads, but only getting 3M bit. I've been on the shorewall firewall and confirmed that I have the firewall configured properly for VOIP QOS. I'm using the basic asterisk iax.conf setup with only those changes required to interface with the teliax service. I have the same issues with both the Sipura Adapter and the Grandstream phones, however, I do believe the Grandstream appears worse at times. I've attempted to analyze the IAX traffic using the Wireshark ethernet protocol analyzer. Everything looks okay best I can tell. What else can I do to analyze why the voice quality is so bad? What can I do in Asterisk to help track down where the problem is? I want to make this VOIP work. Thanks for any help. Jim
Run mtr on your server against the registration server at Teliax and look for bad hops on your route to and fro. If you don't find anything there, you may want to fire up ethereal and capture packets on a few calls and look through them for error data that may be contributing to bad voice quality. I hope this is helpful. Bryan M. Johns Partner Shelton | Johns Technology Group office: 678:248:2637 x:1500 direct: 678:229:1809 mobile: 404.259.9216 iaxtel: 700:248:2637 x:1500 http://www.sheltonjohns.com On Feb 6, 2007, at 8:09 PM, Jim Duda wrote:> I'm struggling to get my VOIP installation to be acceptable. I'm > looking for advice on what else I can look for. > > My system: > o Teliax VOIP service, voip-ny1 proxy > o RCN Cable Internet Service (3Mbps download, 500kbps upload, 6ms > average jitter) > o 3.2 GHZ P4 Server (runs asterisk, firewall, other stuff) > o server lightly loaded > o Linux kernel 2.6.19.2 > o Shorewall Firewall software with QOS configured for VOIP P1 > o Asterisk 1.4.0 > o Sipura SPA-2000 > o Grandstream GXP-2000 > o IAX connection to teliax > > Outbound voice quality is many times horrible, to the point where > ppl say they cannot hear me. The voice often drops out. Inbound > quality seems to cut in and out too. > > I downloaded the myVoipSpeed VOIP analyzer. It indicates that I > have plenty of download and upload bandwidth. I also have good > jitter. The tool doeesn't find any packet loss whatsoever. > > My RCN cable company cannot find anything wrong with my cable > modem. No packet loss. I'm supposed to be paying for 10M bit > downloads, but only getting 3M bit. > > I've been on the shorewall firewall and confirmed that I have the > firewall configured properly for VOIP QOS. > > I'm using the basic asterisk iax.conf setup with only those changes > required to interface with the teliax service. > > I have the same issues with both the Sipura Adapter and the > Grandstream phones, however, I do believe the Grandstream appears > worse at times. > > I've attempted to analyze the IAX traffic using the Wireshark > ethernet protocol analyzer. Everything looks okay best I can tell. > > What else can I do to analyze why the voice quality is so bad? > What can I do in Asterisk to help track down where the problem is? > > I want to make this VOIP work. > > Thanks for any help. > > Jim > > _______________________________________________ > --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-------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.digium.com/pipermail/asterisk-users/attachments/20070206/31726e21/attachment.htm
Jim Duda wrote:> I've been on the shorewall firewall and confirmed that I have the > firewall configured properly for VOIP QOS. >What exactly have you done here? You do know that you are apparently using IAX2 and not SIP. Those are not the same protocols. In fact, if you configured the shorewall system for standard VoIP, that's your problem. IAX2 operates on different ports that SIP. Whereas SIP operates on a control port and then create media ports, IAX2 only uses one. As far as download speed, what have you told shorewall your download speed is? I'm not familiar with it, but just guessing that it's probably like most others. If this is the case, somewhere there is a setting to tell it what your download and upload speed is. 500kpbs up doesn't seem like enough bandwidth to support 10Mpbs down, either.
I have been with Teliax for some time ... Overall I like the service very much ... The key things offered that got me to go with them (having been with VoicePulse and BroadVoice) was live person in tech support and choice of either SIP or IAX trunking ( I have 4xCalls with the plan I bought ) ... However, I also had sound quality issues with them early on when I used IAX ... As soon as I switched to SIP, the problem went away and the quality was outstanding ... Also, the New York gateway you are using was still in BETA last time I checked ... You might want to try using the voip-co1.teliax.com gateway with SIP ... See how that works ... If not, give the tech support guys at Teliax a shot ... I have found them to be quite responsive the few times I have needed them ... G.Hendershot -----Original Message----- From: Jim Duda [mailto:jim@duda.tzo.com] Sent: Tuesday, February 06, 2007 8:10 PM To: asterisk-users@lists.digium.com Subject: [asterisk-users] Help - Poor Voice Quality I'm struggling to get my VOIP installation to be acceptable. I'm looking for advice on what else I can look for. My system: o Teliax VOIP service, voip-ny1 proxy o RCN Cable Internet Service (3Mbps download, 500kbps upload, 6ms average jitter) o 3.2 GHZ P4 Server (runs asterisk, firewall, other stuff) o server lightly loaded o Linux kernel 2.6.19.2 o Shorewall Firewall software with QOS configured for VOIP P1 o Asterisk 1.4.0 o Sipura SPA-2000 o Grandstream GXP-2000 o IAX connection to teliax Outbound voice quality is many times horrible, to the point where ppl say they cannot hear me. The voice often drops out. Inbound quality seems to cut in and out too. I downloaded the myVoipSpeed VOIP analyzer. It indicates that I have plenty of download and upload bandwidth. I also have good jitter. The tool doeesn't find any packet loss whatsoever. My RCN cable company cannot find anything wrong with my cable modem. No packet loss. I'm supposed to be paying for 10M bit downloads, but only getting 3M bit. I've been on the shorewall firewall and confirmed that I have the firewall configured properly for VOIP QOS. I'm using the basic asterisk iax.conf setup with only those changes required to interface with the teliax service. I have the same issues with both the Sipura Adapter and the Grandstream phones, however, I do believe the Grandstream appears worse at times. I've attempted to analyze the IAX traffic using the Wireshark ethernet protocol analyzer. Everything looks okay best I can tell. What else can I do to analyze why the voice quality is so bad? What can I do in Asterisk to help track down where the problem is? I want to make this VOIP work. Thanks for any help. Jim