[Asterisk-Users] Background Noise

[Jess Magnaye]

yes, power is also source of background noise, but not all the time. you
must also have proper grounding.

with pc-phone, it could also be related to your phone/speaker gain controls.
so u have to be definite on what kind of background noise u are getting.

best codec for sip? it's always best to have alaw or ulaw. :) but
bw-consuming. alaw is if u are using E1s. ulaw for T1s.  don't even bother
to use gsm. better get g729.  some says u can use g723.1 with * w/o add'l
purchase of license or something.. but i couldn't make this codec work. (so
i went for g729.. :) ) im testing its quality though as digium cards are
using CPUs as DSPs.




----- Original Message ----- 
From: "Jonathan Biggs" <jon_209 at yahoo.com>
To: <asterisk-users at lists.digium.com>
Sent: Thursday, January 22, 2004 11:01 AM
Subject: Re: [Asterisk-Users] Background Noise


> Just to add some info from recent experience. May
> help,
> May not   1 X100P  2 X 4 port TDM400P
>
> Had to hook a dial-in palm PDA base for a custom
> software implementation to my * system and have the
> modem dial out and work properly.  Phone connects to
> second port on PDA Base
>
> Experienced very bad "electrical" type noise on the
> line, hum, buzz, fad in and out. would come and go.
>
> Switched ports, wires,  rxgain and txgain changes,
> phone changes, nothing helped
>
> the PDA base is also connected via serial port (or USB
> did not matter) to desktop computer for sync purposes
>
> Through trial and error.  Found noise coming from
> connection to desk top computer. On, Off did not
> matter.
>
> Resolution.  The power strip surge protector I was
> using on the desktop computer has two modes for noise
> filtration built in.  75 Hertz (or something, don;t
> remember) and 50 Hertz.  I moved the plug for the
> desktop from the 75 side to the 50 side,  All noise on
> line now gone.
>
> Not sure if this helps, constant noise on all sides
> may be power and noise filtration related...
>
>
>
>
>
> --- "markbalester at libero.it" <markbalester at libero.it>
> wrote:
> > Hi All
> > i have some background noise problem with * and a
> > diva srv 4bri + chan_capi 0.3.0 + X-Ten PRO on my
> > pc.
> > Both in incoming and outgoing call have a background
> > noise.
> >
> > there is some tuning to do?
> > where can i find documentation about capi.conf?
> > which is the best codec for sip (ulaw, alaw,
> > gsm...)?
> >
> > mark
> >
> > _______________________________________________
> > Asterisk-Users mailing list
> > Asterisk-Users at lists.digium.com
> >
> http://lists.digium.com/mailman/listinfo/asterisk-users
> > To UNSUBSCRIBE or update options visit:
> >
> http://lists.digium.com/mailman/listinfo/asterisk-users
>
>
> __________________________________
> Do you Yahoo!?
> Yahoo! SiteBuilder - Free web site building tool. Try it!
> http://webhosting.yahoo.com/ps/sb/
> _______________________________________________
> Asterisk-Users mailing list
> Asterisk-Users at lists.digium.com
> http://lists.digium.com/mailman/listinfo/asterisk-users
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users