[CentOS] A working SIP Phone for Centos44?

Mon Mar 12 10:18:46 UTC 2007
Patrick <centos-list at puzzled.xs4all.nl>

On Mon, 2007-03-12 at 10:37 +0100, Theo Band wrote:
> Theo Band wrote:
> > John R Pierce wrote:
> >> Leonardo Vilela Pinheiro wrote:
> >>>
> >>> On 3/10/07, *Theo Band* wrote:
> >>>
> >>>     I try to find a softphone that works with Asterisk and Centos44, 
> >>> does
> >>>     anyone has a good suggestion or is it better to buy a hardphone?
> >>>
> >>>
> >>> AFAIK, microphone bad quality is more related to the hardware, not 
> >>> the software. My onboard "Intel high definition" sound chipset (ICH7 
> >>> compatible - Intel 945GNT) has a bad output sound, but a much worse 
> >>> input (microphone). I have tried using Windows XP, CentOS, Ubuntu, 
> >>> many softphones (Skype, X-Lite, Ekiga, Twinkle) and definitely the 
> >>> problem is hardware (or all drivers are broken).
> >>
> >> the output quality of the Intel branded motherboards I've used has 
> >> been quite good.   Microphone inputs somewhat less so, but still 
> >> plenty good enough for telephony IF your microphone has high enough 
> >> gain.     If someone  is recording high fidelity (music, etc) from 
> >> microphones, I recommend they get an external microphone preamp and 
> >> use the line input on their sound card, or even better a USB 
> >> input/output box.
> >>
> >> for voice/telephony, USB headsets are the way to go.
> > I also have one trust USB headset and it works, except the volume 
> > cannot be adjusted, it's always max (and that's not nice for a 
> > headset...).
> > I have 20 desktops running FC4/Centos44 on AMD based Motherboards. The 
> > sound is onboard using a Nvidia chipset. Using skype and esd/arts the 
> > sound is very good, no problem. As soon as I try any of the softphones 
> > the mic is heavily distorted. I can even hear a hum as if the ground 
> > shielding is not properly connected. Since skype works so nice (using 
> > eithers OSS or alsa) I expect this to be a software based problem not 
> > hardware. And one softphone is working with FC4 (slfphone) but not on 
> > Centos4.4. The mic sound is less compared to skype (there is a hiss, 
> > when pronouncing the letter 's' the sound is distorted) but upto now 
> > that's the only one that is acceptable for only FC4, not Centos :-(
> >
> Well I tried Twinkle and it works, but on a scale from 0 to 10 I give 
> the sound a 5 were I can give the Skype sound quality a 9+. Strange that 
> it seems to be so difficult to get good sound quality on Centos/FC. My 
> motherboards are A8N32-SLI Deluxe and Foxconn NF4UK8AA-8EKRS both 
> equipped with onboard Realtek ALC 850.
> Has anyone experience (good or bad) with the Realtek ALC 850?

Comparing Skype & Twinkle sound quality is not really fair. The reason
is that Skype uses 16k samples while SIP clients like Twinkle use the
very common 8k samples. Skype will always sound better than standard SIP
clients or POTS. The only VoIP solution I know off that has similar
sound capabilities is Polycom's latest VoIP phone the IP650. Your VoIP
PBX will need to support this too off course or else it will fall back
to the plain old sound.