Hi, I wasn't aware of the difference in quality between landline and mobile phones, or that cellphones use a low bit rate. I did a test again, landline voice quality is better.
>From what you observed, how much drop in quality do I expect when switching from ulaw to g729 for a normal mobile-to-mobile call? On Tue, Jan 17, 2012 at 9:37 PM, Steve Underwood <[email protected]> wrote: > On 01/16/2012 03:59 PM, Roi Stork wrote: >> >> Hi, >> >> We noticed a very sharp drop in voice quality when using digium g729a >> codec. The problem seems to happen if the A channel (caller's channel) >> is a landline/mobile number contacted using the same outgoing provider >> (as a local channel). It sounds like listening to a mono speaker on >> low volume. > > You have conflated two very different things there - landline calls and > cellular calls. A land line to a VoIP user by G.729A should sounds pretty > good. A cellphone to a VoIP user by G.729A should sound *far* worse. > Converting between two different low bit rate codecs really hits the > quality, and all cellphone calls are low bit rate. > >> If I use a softphone that is directly registered to our asterisk box >> the audio quality improves, the words come out more clearer and >> louder. > > You are conflating two things again. Quality and volume are largely > independent issues. > >> I also asked my provider to test call me using their Cisco as5300 >> system and g729 codec and compared it with ulaw. The difference is >> unnoticable. > > Try that again. If you really can't hear the difference you should check > carefully that the system is working as you think it is. If it is, maybe you > should consult a doctor. G.729A is considerably poorer than ulaw. > > Steve > > > > -- > _____________________________________________________________________ > -- 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 -- _____________________________________________________________________ -- 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
