Hi, I’m running into issues receiving faxes which, from what I have read, may be caused by frame slips. While I can find many posts saying to investigate it, I can’t find any that describe **how** to debug the problem. Tried searching this list as well to no avail.
Joe Hi,
Boot the Linux Rescue disk and run memtest86.
Boot Linux but don't go into XWindows.
If you're running software RAID, 'cat /proc/mdstat'. If it's syncing a drive then wait till it's done.
Check 'cat /proc/interrupts' for modules sharing the same interrupt vector. Even an unused USB module, when shared with a Digium module, will cause havoc. If you can, you may 'modprobe -r <name>' the shared module. If you can't, try moving the Digium card to different PCI slots ion order to find an unshared interrupt vector. You can also try assigning irq numbers in BIOS.
Check 'vmstat 1'. With a "quiet" system you should see mostly 100% idle time. How many interrupts are you seeing per one second interval? It should be +/- 1000 for the system timer and +/- 1000 for each Digium card.
If you're seeing a lot of activity on vmstat then turn-off unneeded services.
Pick-up the handset and listen carefully to the dial tone. It should be pure MF tones. If you hear any clicks, pops, or strangeness you know you have a problem. Listen to both the TDM card dialtone as well as the channel bank dialtone (if you have one).
If you have two FXS lines with fax machines, fax a document directly from one to the other. Don't even start with spandsp until this works consistently. If you have both TDM and T-1 then fax TDM->TDM, TDM->CB, CB->TDM, and CB->CB.
After you RxFax a document, open the received .tiff file a tiff viewer or your browser (I use Mozilla). Verify the file contents.
Use TxFax to send the file back to the fax machine. Did it print correctly?
When fax->fax works correctly, try spandsp.
If you still have problems:
If you're on a channel bank (or PSTN circuit) then look at your T-1 timing. In the US you should have something like 'span=1,1,0,esf,b8zs' in zaptel.conf where the T-1 card is taking its timing from the received data stream. The channel bank should be configured to generate its own timing.
If you have IDE drives, try 'hdparm /dev/hdx'. If 32-bit support is 0 then try 'hdparm -c1 /dev/hdx' and 'hdparm -c3 /dev/hdx'. If using_dma is 0 then try 'hdparm -d1 /dev/hdx'. I configured a RAMDISK to eliminate the possibility of disk I/O interfering with spandsp.
Try 'lspci -v' and look at the latency timer for your Digium card(s). You can set it higher with 'setpci -v -s xx:yy.0 LATENCY=TIMER=ff' (xx is the bus number and yy is the slot).
Look at the vmstat output and check for system (not user) spikes every three seconds. If you have spikes then 'modprobe -r wcfxs'--if no more spikes then get a T-1 card and channel bank and try it there.
Good luck. Mike
P.S. Let's keep this thread going--if anyone else has something then please chime in.
-- Michael Welter Introspect Telephony Corp. Denver, Colorado US +1.303.674.2575 [EMAIL PROTECTED] www.introspect.com _______________________________________________ Asterisk-Users mailing list Asterisk-Users@lists.digium.com http://lists.digium.com/mailman/listinfo/asterisk-users To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
