[Asterisk-Users]
Distortion/crackling/skipping problems on outgoing
calls -- please help!!!
Robert Geller
robert at worksofmagic.com
Sat Sep 3 21:50:53 MST 2005
Robert Geller wrote:
> Robert Geller wrote:
>
>> Rich Adamson wrote:
>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> Thank you very much for your response. I do acknowledge that my
>>>> previous posts did not contain much technical information to speak
>>>> of, but it was mainly because I wasn't/am not familiar with the
>>>> Asterisk CLI and troubleshooting Asterisk problems, so I apologize
>>>> for that.
>>>>
>>>> I did get the idea early this morning to try to analyze packets
>>>> with ethereal, and I captured packets when I was made an internal
>>>> IAX call to the Asterisk system (voicemail). I don't really know
>>>> what to look for, but I will learn (again, I'm not very familiar
>>>> with ethereal). Do you hapeople say ve any suggestions for filters
>>>> to use, to evaluate possible packet loss or resending of data?
>>>>
>>>
>>>
>>>
>>> An important item to look at in each packet is the timestamp. In sip
>>> packets, the timestamp should be increasing by 160 for each conseq pkt.
>>> In iax packets, the timestamp should be increasing by 20 for each pkt.
>>>
>>> So if you see a timestamp of 3290 in one pkt and 3310 in the next (a
>>> diff
>>> of 20), that's good. Notice the increasing timestamp value and the
>>> diff.
>>> If pkt 3310 arrives before 3290, then something in the network is
>>> delaying
>>> the delivery of packets so as to cause them to not arrive in the proper
>>> order.
>>>
>>> If there are missing packets, then you'll see timestamps jumping by 40,
>>> 60, 80 or some other value (diff) for iax packets, or, similar for sip
>>> packets.
>>>
>>>
>>>
>>>> Regarding the command that you suggested in the CLI, iax2 show
>>>> netstats, it doesn't recognize that command or anything similar,
>>>> and 'help' doesn't return anything similar that I can see (I'm
>>>> using 1.0.7 if that helps).
>>>>
>>>
>>>
>>>
>>> Since 1.0.7 is rather old (in the scheme of things), I'd suggest you
>>> install something newer to play with. There has been a ton of stuff
>>> that has changed since 1.0.7, but I don't recall if those changes would
>>> have anything to do with your problem. (I use nothing but cvs head, but
>>> I kind of keep an eye on how many changes are happening (and for what
>>> reason), and upgrade when the number of problems seem to be at a low.
>>> The 'iax2 show netstats' would have been added in a later version.
>>>
>>>
>>>
>>>> At this point, I'm thinking that it could be a matter of bad
>>>> cabling or something. The Cat5 cable that's running the 8 or so
>>>> feet from my PC to my router is homemade by me, and many people do
>>>> report problems with homemade cables. I may not have made it
>>>> exactly right, or the untwisted segment may be longer than 1/2",
>>>> which supposedly causes distortion and interference. Perhaps I
>>>> ought to run out and buy a couple factory-made cables to test the
>>>> difference, if any, between them.
>>>>
>>>
>>>
>>>
>>> Replacing the cable would probably be a good start since they are
>>> relatively cheap. Go buy a new one so there's no question about its
>>> quality. Also, keep the cable at least a little distance away from
>>> transformers, ballasts, and other things that tend to generate tons
>>> of electical noise. (Some desk lamps even have extremely noisy
>>> transformers
>>> or ballasts in them.)
>>>
>>>
>>> _______________________________________________
>>> --Bandwidth and Colocation sponsored by Easynews.com --
>>>
>>> Asterisk-Users mailing list
>>> Asterisk-Users at 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
>>>
>>>
>>>
>>>
>>>
>> Your advice was *extremely* helpful. It seems that I learn something
>> new each time I read you all's posts. To me, it looked like each
>> packet was correctly sent at the right interval each time, but I
>> didn't evaluate each one. However, the general trend is that there
>> seems to be no packet loss or resending.
>>
>> I could buy another cable as well, just to be safe, but it seems to
>> me the potential IRQ conflict is more the more likely problem--of
>> course, even when I "ifconfig eth2 down"ed the interface, it still
>> showed up in /proc/interrupts -- does bringing the interface down not
>> completely bring it down? Should I permanently disable it and reboot?
>>
>> Again, thank you very much for your ongoing help; I feel like I'm
>> paying (or ought to) for professional support here. :-)
>>
>> Regards,
>> Robert Geller
>> _______________________________________________
>> --Bandwidth and Colocation sponsored by Easynews.com --
>>
>> Asterisk-Users mailing list
>> Asterisk-Users at 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
>>
>>
>>
> I modprobe -r'ed prism54, the wireless kernel modules for my card, and
> here's what /proc/interrupts looks like:
>
> robert at linux:~/torrents$ cat /proc/interrupts
> CPU0
> 0: 81981003 IO-APIC-edge timer
> 1: 49755 IO-APIC-edge i8042
> 7: 2 IO-APIC-edge parport0
> 8: 1 IO-APIC-edge rtc
> 9: 0 IO-APIC-level acpi
> 12: 499429 IO-APIC-edge i8042
> 14: 224679 IO-APIC-edge ide0
> 15: 900392 IO-APIC-edge ide1
> 169: 0 IO-APIC-level uhci_hcd
> 177: 67917 IO-APIC-level Intel 82801BA-ICH2
> 185: 0 IO-APIC-level uhci_hcd
> 193: 2 IO-APIC-level ohci1394
> 201: 2020679 IO-APIC-level eth0
> NMI: 0
> LOC: 81991943
> ERR: 0
> MIS: 0
>
>
> Well, eth2 isn't even on there, let alone being shared with that Intel
> device. Still, however, the softphone sounds just as bad. Who would
> have thought it was a coincidence that there was IRQ sharing/conflicts
> going on, yet that isn't the soure of my problem?
>
> I'm stumped. I even tried moving the power/surge strip farther away
> from the computer, but it can't be too far away, about 18 inches-2
> feet now.
>
> So, 1) there doesn't *seem* to be any packet loss or incorrect packet
> sending, 2) there are no more IRQ conflicts, and 3) I even tried
> moving my power strip away from the PC. What gives?
> _______________________________________________
> --Bandwidth and Colocation sponsored by Easynews.com --
>
> Asterisk-Users mailing list
> Asterisk-Users at 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
>
>
>
Sorry to write so many consecutive messages in such a short period of
time, but this problem is really bugging me as it has been going on for
days.
When I look in Ethereal, there are actually "two calls" going on -- in
this particular call, Source call #4 and Source call #10318, #4 coming
from the asterisk server and the other one coming from my computer to
the Asterisk server. I don't know why there are two separate "calls,"
but perhaps one of you do. Anyhow, source call #10318 seems fine,
sending a new packet every 20 ms pretty much perfectly and all (although
I do see now that one packet has a timestamp of 33080 and the next has
one of 35060 -- is this something to be concerned about? it doesn't seem
widespread). However, call #4 seems to send every 20 ms, but then there
will be a pause or something in sending, in between which there will be
more packets from source call #10318 which are sent pretty much OK.
Then, the next packet for source call #4 will have a timestamp of
something like 33540, exactly 200 ms after the previous packet from
source call #10318. However, the next packet for SC (source call) #10318
increments 20 ms like it should. Every single packet then on (in this
capture, I recorded about 1500 packets) sends perfectly. iax2.rrdropped,
iax2.rrjitter, and iax2.iax.rrloss returned only 2 packets--the same
two, in the middle of the 1500 packets. So, out of 1500, these are the
only two that seem to have problems.
I don't know what else this could be at this point, but again, thank you
for your help!
More information about the asterisk-users
mailing list