<HTML>
<HEAD>
<TITLE>Audio Clipping with IAXRPT / Web Transceiver Client</TITLE>
</HEAD>
<BODY>
<FONT FACE="Arial"><SPAN STYLE='font-size:12pt'>Good day All.<BR>
<BR>
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.<BR>
<BR>
On our asterisk system, we support three nodes:<BR>
<BR>
27211 – VE3UOR UHF repeater<BR>
29133 – VE3LSR coupled through a RLC-DSP404 controller (often connected to VE3UPS and VE3UHN), and<BR>
29154 – VA3LSR remote link for VE3LSR into VE3MUS – not too active – ad-hoc RF link.<BR>
<BR>
I have also been testing out iaxrpt and the WebTransceiver clients.<BR>
<BR>
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.<BR>
<BR>
It may be that the system is not powered enough to drive the three uri-fobs. CPU show about 25% busy.<BR>
<FONT COLOR="#0000FE">[root@VE3LSR etc]# cat /proc/cpuinfo<BR>
processor : 0<BR>
vendor_id : GenuineIntel<BR>
cpu family : 15<BR>
model : 4<BR>
model name : Intel(R) Pentium(R) 4 CPU 3.00GHz<BR>
stepping : 3<BR>
cpu MHz : 2992.898<BR>
cache size : 2048 KB<BR>
physical id : 0<BR>
siblings : 2<BR>
core id : 0<BR>
cpu cores : 1<BR>
apicid : 0<BR>
fdiv_bug : no<BR>
hlt_bug : no<BR>
f00f_bug : no<BR>
coma_bug : no<BR>
fpu : yes<BR>
fpu_exception : yes<BR>
cpuid level : 5<BR>
wp : yes<BR>
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<BR>
bogomips : 5985.79<BR>
</FONT><BR>
We do think that the system is sufficiently powered.<BR>
<BR>
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. <BR>
<BR>
I am listening to other systems – most not to busy, so I am not yet able to get a good reference point.<BR>
<BR>
I have not dabbled with the codecs much, but have been focused on using ulaw. I am also testing with GSM – lower bandwidth.<BR>
<BR>
So as I said before, thoughts or suggestions are welcome.<BR>
<BR>
Keith / VA3YC<BR>
-- <BR>
<a href="keith@goobie.org">keith@goobie.org</a><BR>
Keith Goobie<BR>
Richmond Hill, ON, CANADA<BR>
</SPAN></FONT>
</BODY>
</HTML>