[Asterisk-Users] FW: [Asterisk-Users, Andrew] Will Echo problems EVER be solved, I'm scared

canuck15 canuck15 at hotmail.com
Wed Aug 24 15:33:44 MST 2005


 
Thank you for the suggestions Andrew.  I have not come across some of them
before and will give them a shot.  Based on my reading, changing the
motherboard should have minimal impact unless that motherboard and the
TDM400P don't get along (aka. IRQ sharing).  I have disabled everything that
is not needed and I do not believe I have any IRQ problems and I am NEVER
wrong ;).  Calls are crisp and clear.  .  No snap, crackle, pop.  It would
be a beautiful thing if not for the echo.

To get the RX/TX levels, run "ztmonitor 1 -vv", dial a telco 1004hz 0dbm
test phone # and set the quantitative RX number to around 14500.  With 2
lines (which I don't have) you test the TX level by looping out to the other
PSTN.  Without a second line you do the simple ztmonitor test for the TX
levels.
http://www.voip-info.org/tiki-index.php?page=Asterisk+zapata+gain+adjustment

I was MOST DEFINITELY NOT wildly changing settings.  It would require a
whole book to explain properly what I did but the end result was that I
pretty much covered every possible combination of settings.  I have read the
white papers and EVERYTHING else I could find on the web to determine the
most logical and proper way to go about this.  I was NOT approaching this
like some back yard six pack scientist.

I made a mistake when I used the word "levels" to describe what fxotune
does.  The bottom line is that it did not change anything.

My settings are pretty much default except where I stated otherwise.
Network is a Linksys WRT54g (ie. Switch).  Asterisk server on port 1,
GXP2000 on port 2, 9133i on port 3.

I have NO echo between SIP phones!

#cat /proc/pci
Bus  0, device   0, function  0:
    Host bridge: Intel Corp. 82815 815 Chipset Host Bridge and Memory
Controller Hub (rev 2).
      Prefetchable 32 bit memory at 0xd0000000 [0xd3ffffff].
  Bus  0, device   1, function  0:
    PCI bridge: Intel Corp. 82815 815 Chipset AGP Bridge (rev 2).
      Master Capable.  Latency=32.  Min Gnt=12.
  Bus  0, device  30, function  0:
    PCI bridge: Intel Corp. 82801BA/CA/DB/EB PCI Bridge (rev 1).
      Master Capable.  No bursts.  Min Gnt=6.
  Bus  0, device  31, function  0:
    ISA bridge: Intel Corp. 82801BA ISA Bridge (LPC) (rev 1).
  Bus  0, device  31, function  1:
    IDE interface: Intel Corp. 82801BA IDE U100 (rev 1).
      I/O at 0xf000 [0xf00f].
  Bus  0, device  31, function  3:
    SMBus: Intel Corp. 82801BA/BAM SMBus (rev 1).
      IRQ 11.
      I/O at 0x5000 [0x500f].
  Bus  1, device   0, function  0:
    VGA compatible controller: ATI Technologies Inc Rage 128 RF/SG AGP (rev
0).
      IRQ 10.
      Master Capable.  Latency=32.  Min Gnt=8.
      Prefetchable 32 bit memory at 0xd4000000 [0xd7ffffff].
      I/O at 0x9000 [0x90ff].
      Non-prefetchable 32 bit memory at 0xd9000000 [0xd9003fff].
  Bus  2, device   1, function  0:
    Unknown mass storage controller: PCI device 1095:3124 (CMD Technology
Inc) (rev 1).
      IRQ 11.
      Master Capable.  Latency=32.
      Non-prefetchable 64 bit memory at 0xdb008000 [0xdb00807f].
      Non-prefetchable 64 bit memory at 0xdb000000 [0xdb007fff].
      I/O at 0xa000 [0xa00f].
  Bus  2, device   2, function  0:
    Communication controller: Tiger Jet Network Inc. Intel 537 (rev 0).
      IRQ 5.
      Master Capable.  Latency=32.  Min Gnt=1.Max Lat=128.
      I/O at 0xa400 [0xa4ff].
      Non-prefetchable 32 bit memory at 0xdb009000 [0xdb009fff].
  Bus  2, device   4, function  0:
    Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL-8139/8139C/8139C+ (rev 16).
      IRQ 10.
      Master Capable.  Latency=32.  Min Gnt=32.Max Lat=64.
      I/O at 0xa800 [0xa8ff].
      Non-prefetchable 32 bit memory at 0xdb00a000 [0xdb00a0ff].


#cat /proc/interrupts
         CPU0
  0:    1290132          XT-PIC  timer
  1:          4          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
  5:   12878920          XT-PIC  wctdm
  8:          1          XT-PIC  rtc
 10:      33866          XT-PIC  eth0
 12:         41          XT-PIC  PS/2 Mouse
 14:      17345          XT-PIC  ide0
 15:         60          XT-PIC  ide1
NMI:          0
ERR:          0



-----Original Message-----
From: Andrew Kohlsmith [mailto:akohlsmith-asterisk at benshaw.com]
Sent: Wednesday, August 24, 2005 1:54 PM
To: asterisk-users at lists.digium.com
Subject: Re: [Asterisk-Users] Will Echo problems EVER be solved, I'm scared

On Wednesday 24 August 2005 16:37, canuck15 wrote:
> As others have recommended, I created a test system with the proposed 
> production parts.  I bought a couple different SIP phones to try and a 
> Digium TDM01B card.  I am using an older PIII 1Ghz system with 
> 815chipset (PCI Rev2.2) with 256MB for my test system.  The only thing 
> that will be different on a production system is that I will be using 
> a newer chipset PC with faster processor and 512MB.  Probably Intel 
> 7505, 7210, or 7211 chipsets which seem to be the most compatible with
Asterisk.

So in other words, everything will be changing on your production system.
Not a good way to start.

> My problem is that I cannot eliminate echo no matter what I try.  I 
> seriously doubt that a newer chipset faster PC with more memory will
> eliminate or even reduce my echo problems based on what I have read.   I
am
> not about to drop more cash to try and find out.  Essentially, my 
> findings are that Asterisk is NOT production capable for my 
> configuration which is via FXO and PSTN.  That is probably THE most 
> common configuration so if it is not production capable like that it 
> isn't production capable period as far as I'm concerned.  What a
disappointment :(.

Most of us don't have any trouble.

> *Buy latest TDM400P with latest FXO module *Ensure copper connection 
> to analog telco lines and telco are not causing problems including 
> running a separate shielded line to the demarc AND having the telco 
> guy come out and test the levels, impedance etc.

I'd be damn curious to know what you got out of this -- most telco guys will
do a basic metallic check, throw on a butt-set and say "yup, I got
dialtone." 
-- hardly a real check but that's neither here nor there.  I'm also in
Canada (1.5hrs from Toronto, ON) so I'm *really* curious who you got on the
line to do a real line test with you.  I have resorted to buying my own
telco test equipment off ebay and using that, even though our techs here are
excellent.

> *Adjust RX/TX levels as per Asterisk Wiki using the quick Ztmonitor 
> method and by using the detailed Ztmonitor method via a Telco 
> 102milliwatt test phone #.  The end result was RX=8.0, TX=-1.0.  Since 
> I still have echo problems I have tried all sort of other settings without
success.

Ok good.  Can you detail exactly what you did to reach these numbers?  I'm
curious.

> *After ALL of the above, try every possible combination of all of the 
> following on Asterisk v1.0.9: echocancel (off, on, 128, 256, 16, 32, 
> 64), echowhenbridged (on, off), echotraining (off, on, 800), Mark 2 
> (default, aggressive, CVS head developments, bugs.digium.com patches, 
> adjust threshold level as per wiki etc. etc.)

I'd posted something earlier that basically says this:  Without measured,
controlled tests, you're just pissing up a rope.  Wildly changing settings
and hoping for the best does nothing but cost you time and energy.

> *Run fxotune which did not find a need to adjust the FXO levels
> (1=0,0,0,0,0,0,0,0)

fxotune doesn't adjust FXO levels, it adjusts a very simple FIR filter which
is part of the DAA in the FXO module.  IMO it helps with audio quality but
not much with echo.

> Still have echo.  Aggressive mode helps a bit but then the other 
> persons voice get's cut off a lot especially when I talk and the 
> cutting in and out of the canceller is more noticeable and 
> objectionable in general than if Aggressive is turned off.

Agressive mode turns the phone line into a half-duplex environment.  When
your voice energy is detected it mutes the receive audio.

> I have two SIP phones.  An Aastra 9133i and a Grandstream GXP2000.  
> Echo problem is the same on both phones.

Do you have echo between the two phones?  What about when calling out to a
VOIP provider, dialing a DID you own that comes back in and hits the other
phone?

> Any comments and/or suggestions would be greatly appreciated as I am 
> pretty much out of ideas and ready to give up on Asterisk as a 
> suitable traditional small business phone system replacement.

I haven't seen your zconfig.h nor your zaptel Makefile, and you didn't tell
us anything about your network (network card, switch, etc.).

My general advice for zaptel is to do the following:
zaptel Makefile: underneath the comments about zconfig.h add
KFLAGS+=-march=pentium4 (or pentium3 or pentiumpro, use the exact proc)
CFLAGS+=-march=pentium4 (or pentium3 or pentiumpro, use the exact proc)

and in zconfig.h
- enable XLAW (optimize for small # of zap channels)
- enable MMX
- MARK2, no agressive mode.

Whenever I've done that my echo has largely disappeared.  

Have you also tried flipping tip and ring going into the TDM card?

-A.




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