[Asterisk-Users] Terrible crackling on analogue line and X100Pcard

[Rich Adamson]

> > What country are you in, and does the chipset on the compat card
> > support the telco standards in your country?
> 
> I'm in the UK. The card was bought in the UK, but from Ebay, so I suppose it 
> could have originated from anywhere. The card dials and answers calls 
> without a problem, so it must be doing *something* right.

Okay. There are two fairly small integrated circuits on the board.
Can you post the part numbers on those chips?

> The card reports itself as:
> 
> 00:02.0 Communication controller: Individual Computers - Jens Schoenfeld 
> Intel 537
> 
> When the wcfxo module loads, dmesg reports:
> 
> Zapata Telephony Interface Registered on major 196
> PCI: Found IRQ 11 for device 0000:00:02.0
> Uhhuh. NMI received. Dazed and confused, but trying to continue
> You probably have a hardware problem with your RAM chips
> wcfxo: DAA mode is 'FCC'
> Found a Wildcard FXO: Generic Clone
> Registered tone zone 4 (United Kingdom)
> 
> The 3rd and 4th lines are suspicous, but I've no idea what they mean. Does 
> it refer to the system RAM or some sort of special RAM on the card? What is 
> NMI?

NMI = non maskable interrupt (or somthing like that). Those messages
would suggest there is a problem with that card and the wcfxo driver.
 
The "mode is FCC" is saying the zaptel drivers are assuming a
card that matches US telco standards. Again, without the chip set
numbers, I can't tell if that card will work correctly in the UK.
If it does not support UK standards, not likely you'll ever get
the echo to go away.

> > If the chipset doesn't match your telco standards, there is a high
> > probability you won't get rid of the echo. If it does match, then try
> > echotraining=800
> > echocancel=yes
> 
> I already use those parameters in zapata.conf, they make no difference :(

Okay, then there is about a 90% chance the card's chip set was
designed for the US telco standards. I'll be able to tell more
once you post those part numbers. 

Are you using a "opermode=UK" or anything like that in /etc/zaptel.conf?
 
> > Regarding the crackling noise, have you checked for shared
> > interrupts (cat /proc/interrupts)?
> 
> This is the output:
> 
>            CPU0
>   0:  211266080          XT-PIC  timer
>   2:          0          XT-PIC  cascade
>   7:     488230          XT-PIC  eth0
>  10:    2113812          XT-PIC  eth1
>  11:  211520617          XT-PIC  aacraid, wcfxo
>  14:         11          XT-PIC  ide0
> NMI:          1
> ERR:         60
> 
> It's sharing an interrupt with the RAID controller. I did try to separate 
> the interrupts when I installed the card, but any combination other than 
> that automatically assigned by the BIOS caused the Linux kernel to fail to 
> even uncompress at boot time, much less boot the system, which struck me as 
> a pretty alarming failure.

It would appear you have several interrupts that aren't being used.
Have you tried looking at the bios setup to see if you can disable
any unused interrupts (like 3 for com1 port)?

If there is nothing in the bios relative to configuring interrupts, then
you only choice is to move the card to other slots in hope of
finding one that assigns a different interrupt.

There is at least a better then 50% chance sharing the interrupt
between the wcfxo driver and the raid controller (#11) is causing
at least some of the crackling noise. You might try establishing
a call and do a large file copy (to exercise the disk) to see if
disk activity causes the noise.
 

> > Go to /usr/src/zaptel directory and run
> > ./zttest
> > Do you get something close to 100% over some period of time?
> 
> Yep:
> 
> # ./zttest
> Opened pseudo zap interface, measuring accuracy...
> 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793%
> 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793% 99.987793%
> 
> Is that good?

Yes, that looks good.

> > What version of asterisk are you running?
> 
> 1.0.7 plus Zaptel of the same version.

You might try going back to an earlier version (or cvs head) to
see if that has any impact on the noise.