[cisco-voip] CF off net low audio issue

Mon Aug 31 17:13:24 EDT 2009

Depends on your hardware. In most cases it is connected POTS-POTS, does 
not have a VOIP leg,  but does still go through DSP's.

/Wes

On Monday, August 31, 2009 4:50:05 PM , Zapp, Brandon D 
<bzapp at sisunet.org> wrote:
> That raises another question in my mind. Does anyone know if a POTs call comes in a router (2811 for example) and leaves that same via POTs does that router convert the call to VOIP or does it stay in the TDM world?
>
>
> Brandon Zapp
> Data Center Operations Analyst
> SISU Medical Systems
> bzapp at sisunet.org
>
>
>
> -----Original Message-----
> From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Countryman, Edward
> Sent: Saturday, August 29, 2009 9:32 PM
> To: Countryman, Edward; Dennis Heim; Nick Matthews
> Cc: cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] CF off net low audio issue
>
> How much do DSP's <on GW> matter?  The problem is after all, coming in POTs and sent right back out POTs, right?
>
> Reason for asking; problem sites have older "DSP-ware".  My newer and larger sites run a significantly newer version; 23.x compared to 9.x at problem sites.  Thoughts??
>
> -----Original Message-----
> From: cisco-voip-bounces at puck.nether.net [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Countryman, Edward
> Sent: Saturday, August 29, 2009 3:00 PM
> To: Dennis Heim; Nick Matthews
> Cc: cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] CF off net low audio issue
>
> Actually it is not.  I have the exact issue at 4 sites which the gain adjustment has improved.  The settings I ended up with are at the extreme ends of their respective ranges so not sure how staff will react come Monday morning.
>
> -----Original Message-----
> From: Dennis Heim [mailto:Dennis.Heim at cdw.com] 
> Sent: Saturday, August 29, 2009 12:56 PM
> To: Countryman, Edward; Nick Matthews
> Cc: cisco-voip at puck.nether.net
> Subject: RE: [cisco-voip] CF off net low audio issue
>
> Is this site out in the middle of no man's land?
>
> Dennis Heim
> Network Voice Engineer
> CDW  Advanced Technology Services
> 11711 N. Meridian Street, Suite 225
> Carmel, IN  46032
>
> 317.569.4255 Office
> 317.569.4201 Fax
> 317.694.6070 Cell
> dennis.heim at cdw.com
> www.berbee.com
>
> -----Original Message-----
> From: Countryman, Edward [mailto:Edward.Countryman at provena.org] 
> Sent: Saturday, August 29, 2009 1:10 PM
> To: Nick Matthews; Dennis Heim
> Cc: cisco-voip at puck.nether.net
> Subject: RE: [cisco-voip] CF off net low audio issue
>
> I was able to crank the input gain and bottom out the output attenuation.  Also required cranking the EC but was able to improve this significantly.  
>
> There is now noticeable popping and hissing on the line but at least the caller can hear the audio.  I am going to also open an att (my carrier) trouble ticket.  Thank you! 
>
> -----Original Message-----
> From: matthn at gmail.com [mailto:matthn at gmail.com] On Behalf Of Nick Matthews
> Sent: Thursday, August 27, 2009 6:17 PM
> To: Dennis Heim
> Cc: Countryman, Edward; cisco-voip at puck.nether.net
> Subject: Re: [cisco-voip] CF off net low audio issue
>
> We see a lot of these cases.
>
> This is generally the cause / scenario:
>
> The PSTN runs a long loop to a site.  At this site, the FXO has low
> volume.  IP phone users don't notice it, because they turn the volume
> up high on the IP phones to compensate.  Then, only call flows that do
> not go through the IP phones have the problem.  What will happen then
> is calls to voicemail, which do not have the IP phone gain configured,
> will be low volume (especially if played back in email and do not go
> back through the phone).  Plus, any calls that come in the system and
> go back out, will have the volume lowered.
>
> What is actually happening is the IP phone users are able to
> workaround the low volume issue themselves.  The real problem is the
> long loop to the router.  If you were to place an analog phone on the
> line instead of the router, you would have the same problem.
>
> The solution is to put input gain on the ports.
>
> voice-port 0/0/0
> input gain 6
>
> This can be done in the middle of a call (live change) to troubleshoot.
>
> The danger is if there is a low signal-to-noise ratio  If this is too
> low, turning up the volume on the line will also make the noise on the
> line very low.  The router has no way to enhance the SNR.  If this is
> the case, your best bet is to find a gain value that makes things as
> good as possible, finding a provider with a closer CO, or having the
> provider try re-running your loop (good luck).
>
>
> -nick
>
> On Thu, Aug 27, 2009 at 11:47 AM, Dennis Heim<Dennis.Heim at cdw.com> wrote:
>   
>> I ended up opening a tac case. Tac has some special tools just for low level
>> analog trouble shooting.
>>
>>
>>
>> Dennis Heim
>> Network Voice Engineer
>> CDW  Advanced Technology Services
>> 11711 N. Meridian Street, Suite 225
>> Carmel, IN  46032
>>
>> 317.569.4255 Office
>> 317.569.4201 Fax
>> 317.694.6070 Cell
>>
>> dennis.heim at cdw.com
>> www.berbee.com
>>
>>
>>
>> From: Countryman, Edward [mailto:Edward.Countryman at provena.org]
>> Sent: Thursday, August 27, 2009 11:46 AM
>> To: Dennis Heim; cisco-voip at puck.nether.net
>> Subject: RE: CF off net low audio issue
>>
>>
>>
>> Do you if there is a Cisco job aid for this type of work;  is most of this
>> done in the router?  I don't necessary see anything on the CCM (mgcp) for
>> this.
>>
>>
>>
>> From: Dennis Heim [mailto:Dennis.Heim at cdw.com]
>> Sent: Thursday, August 27, 2009 10:37 AM
>> To: Countryman, Edward; cisco-voip at puck.nether.net
>> Subject: RE: CF off net low audio issue
>>
>>
>>
>> You will need to play with your input gain and output attenuation.
>> Additional, you may also need to do a tone sweep in order to get things like
>> impedance correctly tuned. Prepare to spend a lot of time to get those
>> analog lines tuned correctly.... Been there done that..
>>
>>
>>
>> Dennis Heim
>> Network Voice Engineer
>> CDW  Advanced Technology Services
>> 11711 N. Meridian Street, Suite 225
>> Carmel, IN  46032
>>
>> 317.569.4255 Office
>> 317.569.4201 Fax
>> 317.694.6070 Cell
>>
>> dennis.heim at cdw.com
>> www.berbee.com
>>
>>
>>
>> From: cisco-voip-bounces at puck.nether.net
>> [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Countryman, Edward
>> Sent: Thursday, August 27, 2009 9:50 AM
>> To: cisco-voip at puck.nether.net
>> Subject: [cisco-voip] CF off net low audio issue
>>
>>
>>
>> I have several smaller physician offices that will forward their main # to
>> an offsite answering service for after hours coverage.  The sites are all
>> trunked with POTS lines connected to FXO ports on 28xx series ISRs.  So the
>> incoming call on FXO port 1 effectively is sent back out on FXO port 2 etc.
>>
>>
>>
>> The problem I have is that the audio level the caller hears is greatly
>> attenuated; almost beyond discernment.  However if I call the far end
>> directly the call is very clear so it appears my router is the problem.
>>
>>
>>
>> Anyone have any thoughts on this?
>>
>>
>>
>> _______________________________________________
>> cisco-voip mailing list
>> cisco-voip at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/cisco-voip
>>
>>
>>     
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