Hi, I'm experiencing a few (but meaningful) cases of audio distortion (or bad quality). I can't say yet how often this happens. Please listen to the following sound file: http://213.96.91.201/temp/distorted_audio_1.wav This was recorded by Asterisk while the local SIP caller was dialing out a SIP trunk (so the problem is on my side, definitely, and it doesn't seem to be related to the bandwidth between my peer and the SIP provider). You can hear a scratchy sound during the whole fragment. I can't determine the possible cause of this kind of distortion. Maybe an expert ear can give me a clue. It shouldn't be the Asterisk server's CPU usage. Could it be a network issue between the Asterisk system and the SIP client? (it happens with SIP hardphones as well as softphones so I guess it's improbable it's the client software/firmware) Both softphones and hardphones use GSM and usually work fine (this kind of issue is not too frequent). The LAN isn't dedicated to voice but has QoS prioritizing VoIP. Could the cause of the distortion be network-related? And only on "my" side? Should I consider other causes? Thanks, Vieri
Hi Vieri, The sound I hear does not seem caused by packet loss, jitter or latency, this problems usually produces a robotic or synthetic voice. It seems produced by some kind of bad contact (most probable). It is strange that you are seeing it using hard phones, I could bet on the headphones. Check also for electric interference, it is very common for line filters to break (broken capacitor usually) causing this kind of interference. Try also a different codec such as G.711 (improbable). Flavio E. Goncalves www.asteriskguide.com 2010/4/9 Vieri <rentorbuy at yahoo.com>> Hi, > > I'm experiencing a few (but meaningful) cases of audio distortion (or bad > quality). I can't say yet how often this happens. > > Please listen to the following sound file: > > http://213.96.91.201/temp/distorted_audio_1.wav > > This was recorded by Asterisk while the local SIP caller was dialing out a > SIP trunk (so the problem is on my side, definitely, and it doesn't seem to > be related to the bandwidth between my peer and the SIP provider). You can > hear a scratchy sound during the whole fragment. > > I can't determine the possible cause of this kind of distortion. Maybe an > expert ear can give me a clue. It shouldn't be the Asterisk server's CPU > usage. Could it be a network issue between the Asterisk system and the SIP > client? (it happens with SIP hardphones as well as softphones so I guess > it's improbable it's the client software/firmware) Both softphones and > hardphones use GSM and usually work fine (this kind of issue is not too > frequent). The LAN isn't dedicated to voice but has QoS prioritizing VoIP. > > Could the cause of the distortion be network-related? And only on "my" > side? Should I consider other causes? > > Thanks, > > Vieri > > > > > > -- > _____________________________________________________________________ > -- Bandwidth and Colocation Provided by http://www.api-digital.com -- > New to Asterisk? Join us for a live introductory webinar every Thurs: > http://www.asterisk.org/hello > > 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/20100409/e787e590/attachment.htm
Am 09.04.2010 13:10, schrieb Vieri:> Please listen to the following sound file:I've experienced similar (well, vaguely similar) distortion on a "horstbox pro" when echo cancellation is switched on for the zap channels (ISDN). Turning it off resulted in no distortion at all, but then i experienced very strong echo at times. Switching on echotraining lowered the distortion so that's currently the trade-off i have to live with. HTH a little. -- -- o
Hi, sounds for me like when i use an headset and the microfone handle scratches on my beard while i talk ;) maybe you have a network cable whitout screening. I had bad problems on different phones which sounds like that you have cause of electric or magnetic inteferences but when i changed the network cable everything was fine again. do you have made an echo test lie exten => 999,1,Echo() to hear yourself and try to find this issue. best regards steve smith Vieri schrieb:> Hi, > > I'm experiencing a few (but meaningful) cases of audio distortion (or bad quality). I can't say yet how often this happens. > > Please listen to the following sound file: > > http://213.96.91.201/temp/distorted_audio_1.wav > > This was recorded by Asterisk while the local SIP caller was dialing out a SIP trunk (so the problem is on my side, definitely, and it doesn't seem to be related to the bandwidth between my peer and the SIP provider). You can hear a scratchy sound during the whole fragment. > > I can't determine the possible cause of this kind of distortion. Maybe an expert ear can give me a clue. It shouldn't be the Asterisk server's CPU usage. Could it be a network issue between the Asterisk system and the SIP client? (it happens with SIP hardphones as well as softphones so I guess it's improbable it's the client software/firmware) Both softphones and hardphones use GSM and usually work fine (this kind of issue is not too frequent). The LAN isn't dedicated to voice but has QoS prioritizing VoIP. > > Could the cause of the distortion be network-related? And only on "my" side? Should I consider other causes? > > Thanks, > > Vieri > > > > > >