Anton,

Thanks for the input. I wasn't aware of ngrep. I'll check it out. A packet 
analyzer is a good idea. I am accustomed to using a packet analyzer mostly in a 
"reactive" approach, or during an incident. Are you suggesting that I just 
setup a capture to be running continuously until we become aware of the 
problem, and then at that point, review it to see what really happened 
(regarding what was & was not transmitted on the network)?

Also, thanks for the link in the Asterisk Cookbook. I'll check it out.

>From your egrep example here:
tail -f /var/log/asterisk/full | egrep --color -w 
'chan_sip.*SIP/911|pbx.*SIP/911'

Are you basically using 911 as an example extension that we wanted to see 
logging for? That seems useful. Thanks. FYI, I grepped for chan_sip, and pbx, 
but didn't really get anything from those with any SIP extension logging. Could 
that be because I'm using asterisk 1.4? FYI, the customer I'm troubleshooting 
for is using 1.6, so maybe it would give me something on their version....?

Still one of my concerns is the ability to follow an inbound call from the time 
it hits asterisk, until it is finally gone. I'd like to follow the call through 
the logging to have a logical view of what happened to the call from the time 
it rang in (where the call got sent to [time conditions, queues, ring groups, 
extensions, transfers, etc.], what phones were rung trying to connect the call, 
etc.

Any way I this can be done? Can't a call be passed off from one channel to 
another, which would leave me with only seeing a part of the logs for the life 
of the call if I only grep the logs based on one channel id?

Thanks,
-
Doug Mortensen
Network Consultant
Impala Networks
P: 505.327.7300

From: Anton Kvashenkin [mailto:[email protected]]
Sent: Thursday, October 27, 2011 8:27 AM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Tips & best practices for asterisk 
troubleshooting & parsing logs

Capture pcap with tshark or tcpdump for the future analysis with wireshark. 
Ngrep is also handy tool for captaring, say, INVITE. You can use grep like 
this: tail -f /var/log/asterisk/full | egrep --color -w 
'chan_sip.*SIP/911|pbx.*SIP/911'
Interesting technique from Astresk Cookbook, "Debugging dialplan with Verbose() 
http://ofps.oreilly.com/titles/9781449303822/DialplanFundamentals.html
2011/10/27 Sammy Govind <[email protected]<mailto:[email protected]>>
It was a challenge to read through all the interesting experience you've shared 
over here. I don't know what others may be using for parsing the logs 
beautifully and make them usable. What I would recommend you at the very 
beginning ,since you mentioned using egrep, is figure out the Channel 
identifier string from the logs for a particular call. That's underlined below 
for you.

[Oct 26 17:58:01] VERBOSE[14274] logger.c:     -- Executing [s@tc-maint:3] 
System("Local/s@tc-maint-2496,2","/var/lib/asterisk/bin/schedtc.php 60 
/var/spool/asterisk/outgoing 0") in new stack

Once you Figure out this part use egrep tool and you'll end up seeing only the 
data related to this particular call.

More advanced tool or techniques may involve setting up a central logging 
server where all the other servers deposit their logs and use monitoring tools 
like swatch, splunk, zabbix etc etc etc to parse the logs for you and generate 
alerts.

I haven't came across any Asterisk-specific log parser utility so far. 
Honestly, I never needed one.

On Thu, Oct 27, 2011 at 5:16 AM, Douglas Mortensen 
<[email protected]<mailto:[email protected]>> wrote:
Hello all,

I have been running asterisk systems since summer of 2008. I do not claim to be 
an expert. But I have worked through many issues during this period. I have 
setup & manage 5 systems, which serve 6 companies total (and of course process 
calls for all of the people they do business with).

I have always been happy with asterisk (well, obviously less happy during the 
problem times... :-). And I continue to prefer to us it. However, if I could 
name the one largest struggle that I have with asterisk, it is the facilities 
that it provides for troubleshooting issues & parsing logs.

I am hoping that someone on this mailing list can help me to realize how 
ignorant I really am, and how much time I have wasted parsing, "grep"ping & 
"less"ing logs manually. I am hoping that one of you can help me "see the 
light". If so, I would be most grateful.

Specifically, here are the challenges I encounter, which I would desperately 
appreciate help with:

Here's an example scenario:

A customer calls me & says that a call just came in & some of their wireless 
DECT phones (I know, trouble already.... :-) didn't ring, while others did. I 
tell the customer that I'll start looking into the problem immediately.

I am using AsteriskNOW with asterisk 1.6. So I SSH into the system & cd to 
/var/log/asterisk & start looking at the "full" log via "less". We have 
configured the bulk of our system via FreePBX 2.9. Inbound calls are routed 
first to a time condition which checks whether it is after hours. If it is not 
afterhours, then are then routed to a queue, which rings all phones (4 wireless 
DECT phones on 1 DECT wireless server that registers the SIP extensions on 
behalf of its 4 phones, and 4 more wireless DECT phones on their own wireless 
server configured the same, and an ATA connected to a paging amp that rings a 
loud speaker). From there, someone typically will answer the call. Often times 
they then transfer the call to another extension. However, sometimes no one 
answers the call, and it winds up going to VM.

>From the logging aspect of asterisk, it has usually felt like I am trudging 
>through a swampy marsh trying to put the bits & pieces together. The challenge 
>I've seen is that the above scenario can actually consist of multiple SIP 
>calls w/ different legs. I *think* (but am not 100% sure) that often times a 
>call can be handed off from 1 asterisk process to another. The result is that 
>"grep"ping by the asterisk process ID shown after the VERBOSE (or NOTICE or 
>DEBUG section [see below]), I don't actually get to see the full sequence of 
>events in following  all logging that is relevant to that phone call.

[Oct 26 17:58:01] VERBOSE[14274] logger.c:     -- Executing [s@tc-maint:3] 
System("Local/s@tc-maint-2496,2","/var/lib/asterisk/bin/schedtc.php 60 
/var/spool/asterisk/outgoing 0") in new stack

Then on a busy asterisk system, if I filter by the process id, the one process 
that starts handling the call originally, may wind up immediately taking on 
another totally unrelated call after handing the initial call off to another 
process. If I am not extremely careful, I may wind up mistaking the log lines 
for the 2nd call, as being a part of the 1st call, and then I'm totally barking 
up the wrong tree.... :-)

Another option I've tried is to enable SIP debugging. Generally, I do like 
this. And one nice thing is that asterisk seems to usually add the SIP "Date:" 
parameter with its SIP invites, etc. The result is that I can grep the asterisk 
log like this `egrep -v ^"\[" full` (SIP debug lines don't have the standard 
timestamp at the beginning) and then I'm only seeing the SIP debugging, in a 
pretty clean output. Still, there can be a LOT of SIP traffic going on, when 
I'm ringing 9 different extensions from a queue. Trying to parse it all can 
make me go cross-eyed. :-) And doing so can take a LONG time (30+ minutes). The 
SIP debug lines don't necessarily tell me which call they correspond with. So 
if there are multiple calls going on or ringing at the same time, this can 
really get hairy.

So more or less, I think I've sort of established the type of experience I have 
with parsing the asterisk logging in troubleshooting issues. Ultimately, I 
usually can get to the bottom of it, but it literally probably takes 45-60+ 
minutes of just parsing through the log files before I even get to the point, 
of being able to answer some seemingly simple questions.

Am I going about this the wrong way? Please say yes. Because this is literally 
probably the only challenge (& sometimes frustration) I have with asterisk. Are 
there [much] better ways to go about this?

I did a bit of searching online, and it seems that some people have attempted 
to create tools to parse & display the asterisk full log in a more structured 
simplified manner. But my initial impression was that these were more of "good 
ideas" that people started on, but they haven't really matured to the point of 
being really helpful with these types of situations.

A part of me just thinks that it just shouldn't be so hard to be able to tell 
whether a certain extension did actually get a SIP INVITE sent to it, or 
whether it responded, or to simply just follow the chain of the route that a 
call took through asterisk prior to running into trouble (or just where it 
ended up).

It seems to me that there should be some powerful tool that does the hard work 
of parsing the related log lines for us, so that we can just *quickly* review 
its output & see the sequence of events to determine exactly what happened.

Only when we find out what happened, can we even start working on the solution.

If you have some insight into reviewing, filtering & parsing asterisk logs in 
the process of troubleshooting issues, I would GREATLY appreciate it.

What approach would you take? What are the best practices, tips & secrets that 
you've developed?

Thanks all!
-
Doug Mortensen
Network Consultant
Impala Networks Inc
CCNA, MCSA, Security+, A+
Linux+, Network+, Server+
A.A.S. Information Technology
.
www.impalanetworks.com<http://www.impalanetworks.com>
P: (505) 327-7300<tel:%28505%29%20327-7300>
F: (505) 327-7545<tel:%28505%29%20327-7545>


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