[App_rpt-users] [Bulk] Audio Clipping with IAXRPT / Web Transceiver Client

[Keith Goobie]

Benjamin

I have an RV042 router and I have established priority handling for iAX VoIP
packets.

WE will get a service monitor into play.  We just have to schedule some site
time.

I do agree that there are a lot of variables out there.

WE do have some nodes to reference locally.

Keith


On 3/3/13 8:03 PM, "Benjamin L. Naber" <Benjamin at kb9lfz.com> wrote:

> Somethings I would check on.
> 
> Use the radio-tune-menu to ensure with a service monitor to ensure the
> TX and RX audio levels correctly. Remove any possibility the "Distant
> End" is having difficulty.
> 
> Also, while you might still have a great internet connection, you may
> still suffer poor VoIP service because of Quality of Service (QoS)
> implemented on the routers you are connected to. I've run into many
> businesses with 50-100Mb internet connections and the VoIP audio sucks
> because there was no prioritization of VoIP packets.
> 
> Test your setup with stations that have properly set audio levels, via
> RF, and connected to another node. Allstar nodes 2130 and 2560 seem to
> have their stuff together. You also be able to call into the Allstar
> telephone portal (763) 230-0000, and connect to your node that way to do
> some "for grins" testing.
> 
> What is beyond anyone's reasonable control is whether or not the users
> of your system, or anyones for that matter, have properly set audio
> levels on their rigs. HTs seem to be the biggest offenders of having
> mis-tuned TX audio.
> 
> As mentioned before, you do not need to have a real power node to run
> Allstar. I run Limey Linux on a 1GHz thin client with zero problems. I
> have my router setup for QoS of VoIP packets, and so far I've had zero
> issues with any type of audio issues.
> 
> ~Benjamin, KB9LFZ
> Allstar 28569
> 
> 
> 
> On Sun, 2013-03-03 at 11:31 -0500, Keith Goobie wrote:
>> Good day All.
>> 
>> We have had our node up at VE3LSR / VE3UOR for a few months and we all
>> have learned a lot about configuration and operation.  It is ACID
>> install and version id is 300.3.
>> 
>> On our asterisk system, we support three nodes:
>> 
>> 27211 ­ VE3UOR UHF repeater
>> 29133 ­ VE3LSR coupled through a RLC-DSP404 controller (often
>> connected to VE3UPS and VE3UHN), and
>> 29154 ­ VA3LSR remote link for VE3LSR into VE3MUS ­ not too active ­
>> ad-hoc RF link.
>> 
>> I have also been testing out iaxrpt and the WebTransceiver clients.
>> 
>> I am on these systems and the results have been promising.  I do
>> notice some clipping on the audio on some stations.  Initially I
>> thought it was amplitude related ­ over-driving the URI-FOB, but I am
>> now beginning to suspect that it may be network related and in my
>> research I hear the term jitter being used ­ which if activated,
>> adjust operation on the receiving end only.
>> 
>> It may be that the system is not powered enough to drive the three
>> uri-fobs.   CPU show about 25% busy.
>> [root at VE3LSR etc]# cat /proc/cpuinfo
>> processor    : 0
>> vendor_id    : GenuineIntel
>> cpu family    : 15
>> model        : 4
>> model name    : Intel(R) Pentium(R) 4 CPU 3.00GHz
>> stepping    : 3
>> cpu MHz        : 2992.898
>> cache size    : 2048 KB
>> physical id    : 0
>> siblings    : 2
>> core id        : 0
>> cpu cores    : 1
>> apicid        : 0
>> fdiv_bug    : no
>> hlt_bug        : no
>> f00f_bug    : no
>> coma_bug    : no
>> fpu        : yes
>> fpu_exception    : yes
>> cpuid level    : 5
>> wp        : yes
>> flags        : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca
>> cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm
>> constant_tsc pni monitor ds_cpl est cid cx16 xtpr
>> bogomips    : 5985.79
>> 
>> We do think that the system is sufficiently powered.
>> 
>> We are looking for comments & guidance.  Are we expecting too much
>> from the system having three fobs connected?  We do have good
>> bandwidth into and out of the site.
>> 
>> I am listening to other systems ­ most not to busy, so I am not yet
>> able to get a good reference point.
>> 
>> I have not dabbled with the codecs much, but have been focused on
>> using ulaw.  I am also testing with GSM ­ lower bandwidth.
>> 
>> So as I said before, thoughts or suggestions are welcome.
>> 
>> Keith / VA3YC
>> -- 
>> keith at goobie.org
>> Keith Goobie
>> Richmond Hill, ON, CANADA
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> 
> 

-- 
keith at goobie.org
Keith Goobie
Richmond Hill, ON, CANADA