<div><div dir="auto">I have a question on this, since 180 arrived before the 200, shouldn’t it go out before? I.e.: FIFO? Or is this not happening because there are multiple processes and one may take the 180 and the other the 200 and they are processes independently?</div><div dir="auto"><br></div><div dir="auto">I guess setting the childs to only 1 should prove this theory.</div><div dir="auto"><br></div><div dir="auto">David</div></div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, 8 Apr 2020 at 16:51, Luis Rojas G. <<a href="mailto:luis.rojas@sixbell.com">luis.rojas@sixbell.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">
<div>
<div>Hi, Henning,</div>
<div><br>
</div>
<div>No need to be ironic. As I mentioned on
my first post, I tried stateful proxy and I observed the same
behavior. <br>
<br>
<i>"I tried using stateful proxy and I obtained the same result."</i><br>
<br>
The asynchronous sleep seems promising. I will look into it.<br>
<br>
Thanks,</div>
<div><br>
</div>
<div>Luis</div></div><div><div><br>
<br>
<br>
On 4/8/20 9:30 AM, Henning Westerholt wrote:<br>
</div>
<blockquote type="cite">
<div>
<p class="MsoNormal"><span>Hi
Luis,<u></u><u></u></span></p>
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">I see. Well, you want to use Kamailio as a
stateless proxy, on the other hand it should do things that
are inherently stateful.
</span><span lang="EN-GB">😉</span><span lang="EN-GB"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">As mentioned, have a look to the dialog module
to track the state of dialogs that you process. This will
not work in a stateless mode, though.
<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">You can also use the htable module to just
store some data about the processed messages in a shared
memory table and use this to enforce your ordering. There is
also the option to do an asynchronous sleep (with the async)
module on the message that you want to delay but still
processing other messages during it.<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Cheers,<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Henning<u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<div>
<p class="MsoNormal"><span lang="EN-GB">-- <u></u>
<u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Henning Westerholt –
</span><span><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fskalatan.de%2Fblog%2F&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311846648&sdata=Rlxmq4vieb20HKUi4se4MfGJSuETpO%2Bd8uK0KzBTWO0%3D&reserved=0" target="_blank"><span style="color:rgb(5,99,193)" lang="EN-GB">https://skalatan.de/blog/</span></a></span><span lang="EN-GB"><u></u><u></u></span></p>
<p class="MsoNormal"><span lang="EN-GB">Kamailio services –
</span><span><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgilawa.com%2F&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311846648&sdata=nAvHd08RTXoEAFfpOuoGQJnoRmOtzQ0RSfS2RYwIyQs%3D&reserved=0" target="_blank"><span style="color:rgb(5,99,193)" lang="EN-GB">https://gilawa.com</span></a></span><span>
<span lang="EN-GB"><u></u><u></u></span></span></p>
</div>
<p class="MsoNormal"><span lang="EN-GB"><u></u> <u></u></span></p>
<div>
<div style="border-style:solid none none;border-top-width:1pt;padding:3pt 0cm 0cm;border-top-color:rgb(225,225,225)">
<p class="MsoNormal" style="margin-left:35.4pt"><b>From:</b>
Luis Rojas G. <a href="mailto:luis.rojas@sixbell.com" target="_blank"><luis.rojas@sixbell.com></a>
<br>
<b>Sent:</b> Wednesday, April 8, 2020 3:00 PM<br>
<b>To:</b> Henning Westerholt <a href="mailto:hw@skalatan.de" target="_blank"><hw@skalatan.de></a>;
Kamailio (SER) - Users Mailing List
<a href="mailto:sr-users@lists.kamailio.org" target="_blank"><sr-users@lists.kamailio.org></a><br>
<b>Subject:</b> Re: [SR-Users] Kamailio propagates 180 and
200 OK OUT OF ORDER<u></u><u></u></p>
</div>
</div>
<p class="MsoNormal" style="margin-left:35.4pt"><u></u> <u></u></p>
<div>
<p class="MsoNormal" style="margin-left:35.4pt">Hello,
Henning,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:35.4pt"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:35.4pt">I am worried
about this scenario, because it's a symptom of what may
happen in other cases. For instance, I've seen that this
operator usually sends re-invites immediate after sending
ACK. This may create race conditions like 3.1.5 of RFC5407<br>
<br>
<a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftools.ietf.org%2Fhtml%2Frfc5407%23page-22&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311856645&sdata=fwVfaNyZ7hCyBvYz%2BdlWBMf52MuFdhBxHpnYysjA0FA%3D&reserved=0" target="_blank">https://tools.ietf.org/html/rfc5407#page-22</a><br>
<br>
I'd understand that one happens because of packet loss, as
it's in UDP's nature, but in this case it would be
artificially created by Kamailio. if there was no problem at
network level (packet loss, packets following different path
on the network and arriving out of order), why Kamailio
creates it? <br>
<br>
I'd expect that the shared memory is used precisely for
this. If an instance of kamailio receives a 200 OK, it could
check on the shm and say "hey, another instance is
processing a 180 for this call. Let's wait for it to finish"
(*). I know there could still be a problem, the instance
processing the 180 undergoes a context switch just after it
receives the message, but before writing to shm, but it
would greatly reduce the chance.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:35.4pt"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-right:0cm;margin-bottom:12pt;margin-left:35.4pt">In
our applications we use a SIP stack that always sends
messages to the application in the same order it receives
them, even though is multi-threaded and messages from the
network are received by different threads. So, they really
syncronize between them. Why Kamailio instances don't?<br>
<br>
I am evaluating kamailio to use it as a dispatcher to
balance load against our several Application Servers, to
present to the operator just a couple of entrance points to
our platform (they don't want to establish connections to
each one of our servers). This operator is very difficult to
deal with. I am sure they will complain something like "why
are you sending messages out of order? Fix that". The
operator will be able to see traces and check that messages
entered the Kamailio nodes in order and left out of order.
They will not accept it.<br>
<br>
(*) Not really "wait", as it would introduce a delay in
processing all messages. it should be like putting it on a
queue, continue processing other messages, and go back to
the queue later.<br>
<br>
Well, thanks for your answer.<br>
<br>
Luis<br>
<br>
<br>
<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:35.4pt"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:35.4pt"><br>
On 4/8/20 3:01 AM, Henning Westerholt wrote:<u></u><u></u></p>
</div>
<blockquote style="margin-top:5pt;margin-bottom:5pt">
<p class="MsoNormal" style="margin-left:35.4pt"><span>Hello Luis,</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">as the 1xx
responses are usually send unreliable (unless you use
PRACK), you should not make any assumption on the order or
even the arrival of this messages. It can also happens on
a network level, if send by UDP.</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">Can you
elaborate why you think this re-ordering is a problem for
you?</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">One idea
to enforce some ordering would be to use the dialog module
in combination with reply routes and the textops(x)
module.</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">About the
shared memory question – Kamailio implement its own memory
manager (private memory and shared memory pool).</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">Cheers,</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">Henning</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<div>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">--
</span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">Henning
Westerholt –
</span><span><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fskalatan.de%2Fblog%2F&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311866648&sdata=HCaqkR5PR6BmByZVV5%2F59XWfNywkkedMaujpDOOG4dk%3D&reserved=0" target="_blank"><span style="color:rgb(5,99,193)" lang="EN-GB">https://skalatan.de/blog/</span></a></span><u></u><u></u></p>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB">Kamailio
services –
</span><span><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgilawa.com%2F&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311866648&sdata=O1BqU4CI4M6M8OUaE10JvFbJIeH32uZRuQg3ihEkxN0%3D&reserved=0" target="_blank"><span style="color:rgb(5,99,193)" lang="EN-GB">https://gilawa.com</span></a>
</span><u></u><u></u></p>
</div>
<p class="MsoNormal" style="margin-left:35.4pt"><span lang="EN-GB"> </span><u></u><u></u></p>
<div>
<div style="border-style:solid none none;border-top-width:1pt;padding:3pt 0cm 0cm;border-top-color:rgb(225,225,225)">
<p class="MsoNormal" style="margin-left:70.8pt"><b>From:</b>
sr-users <a href="mailto:sr-users-bounces@lists.kamailio.org" target="_blank">
<sr-users-bounces@lists.kamailio.org></a> <b>On
Behalf Of </b>Luis Rojas G.<br>
<b>Sent:</b> Tuesday, April 7, 2020 10:43 PM<br>
<b>To:</b> <a href="mailto:sr-users@lists.kamailio.org" target="_blank">sr-users@lists.kamailio.org</a><br>
<b>Subject:</b> [SR-Users] Kamailio propagates 180 and
200 OK OUT OF ORDER<u></u><u></u></p>
</div>
</div>
<p class="MsoNormal" style="margin-left:70.8pt"> <u></u><u></u></p>
<div>
<p style="margin-left:70.8pt">Good day,<u></u><u></u></p>
<p style="margin-left:70.8pt">I am testing the dispatcher
module, using Kamailio as stateless proxy. I have a pool
of UAC (scripts in SIPP) and a pool of UAS (also scripts
in SIPP) for the destinations. Kamailio version is
kamailio-5.3.3-4.1.x86_64.<u></u><u></u></p>
<p style="margin-left:70.8pt">Problem I have is, if UAS
responds 180 and 200 OK to Invite immediately, sometimes
they are propagated out of order. 200 OK before 180, like
this :<u></u><u></u></p>
<p style="margin-right:0cm;margin-bottom:12pt;margin-left:70.8pt"><img src="cid:1715a7ea85ead7999131" border="0" style="width:597px;max-width:100%"><u></u><u></u></p>
<p style="margin-left:70.8pt">UAS is <a href="http://172.30.4.195:5061" target="_blank">172.30.4.195:5061</a>. UAC
is <a href="http://172.30.4.195:5080" target="_blank">172.30.4.195:5080</a>. Kamailio is <a href="http://192.168.253.4:5070" target="_blank">192.168.253.4:5070</a><u></u><u></u></p>
<p style="margin-left:70.8pt">Difference between 180 and 200
is just about 50 microseconds.
<u></u><u></u></p>
<p style="margin-left:70.8pt">My guess is that both messages
are received by different instances of Kamailio, and then
because of context switches, even though the 180 is
received before, that process ends after the processing of
200. However, I had the idea that in order to avoid these
problems the kamailio processes synchronized with each
other using a shared memory. I tried using stateful proxy
and I obtained the same result.<u></u><u></u></p>
<p style="margin-left:70.8pt">By the way, anyone has any
idea about how Kamailio's share memory is implemented? It
clearly does not use the typical system calls shmget(),
shmat(), because they are not shown by ipcs command.<u></u><u></u></p>
<p style="margin-left:70.8pt">Before posting here I googled,
but I couldn't find anything related to this. I can't
believe I am the only one who ever had this problem, so I
guess I am doing something wrong...<u></u><u></u></p>
<p style="margin-left:70.8pt">Please, any help. I'm really
stuck on this.<u></u><u></u></p>
<p style="margin-left:70.8pt">Thanks.<u></u><u></u></p>
<pre style="margin-left:70.8pt;font-family:monospace">-- <u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
</div>
</blockquote>
<p style="margin-left:35.4pt"><u></u> <u></u></p>
<pre style="margin-left:35.4pt;font-family:monospace">-- <u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace">Luis Rojas<u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace">Software Architect<u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace">Sixbell<u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace"><a href="https://www.google.com/maps/search/Los+Leones+1200+%0D%0A+++++++++Providencia+%0D%0A+++++++++Santiago,+Chile?entry=gmail&source=g" style="font-family:monospace">Los Leones 1200</a><u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace"><a href="https://www.google.com/maps/search/Los+Leones+1200+%0D%0A+++++++++Providencia+%0D%0A+++++++++Santiago,+Chile?entry=gmail&source=g" style="font-family:monospace">Providencia</a><u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre><a href="https://www.google.com/maps/search/Los+Leones+1200+%0D%0A+++++++++Providencia+%0D%0A+++++++++Santiago,+Chile?entry=gmail&source=g">
</a><pre style="margin-left:35.4pt;font-family:monospace"><a href="https://www.google.com/maps/search/Los+Leones+1200+%0D%0A+++++++++Providencia+%0D%0A+++++++++Santiago,+Chile?entry=gmail&source=g" style="font-family:monospace">Santiago, Chile</a><u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre><a href="https://www.google.com/maps/search/Los+Leones+1200+%0D%0A+++++++++Providencia+%0D%0A+++++++++Santiago,+Chile?entry=gmail&source=g">
</a><pre style="margin-left:35.4pt;font-family:monospace">Phone: (+56-2) 22001288<u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace"><a href="mailto:luis.rojas@sixbell.com" target="_blank" style="font-family:monospace">mailto:luis.rojas@sixbell.com</a><u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
<pre style="margin-left:35.4pt;font-family:monospace"><a href="https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.sixbell.com%2F&data=02%7C01%7C%7C365ec3c445394a3b0dfa08d7dbc0fe3a%7Cab4a33c2b5614f798601bc921698ad08%7C0%7C0%7C637219494311876634&sdata=25KyYHDQz9BU3XDEGdjjPHgRH4MCZIFOEyXeXUoKjzI%3D&reserved=0" target="_blank" style="font-family:monospace">http://www.sixbell.com</a><u style="font-family:monospace"></u><u style="font-family:monospace"></u></pre>
</div>
</blockquote>
<p><br>
</p>
<pre cols="72" style="font-family:monospace">--
Luis Rojas
Software Architect
Sixbell
<a href="https://www.google.com/maps/search/Los+Leones+1200%0D%0AProvidencia%0D%0ASantiago,+Chile?entry=gmail&source=g" style="font-family:monospace">Los Leones 1200
Providencia
Santiago, Chile</a>
Phone: (+56-2) 22001288
<a href="mailto:luis.rojas@sixbell.com" target="_blank" style="font-family:monospace">mailto:luis.rojas@sixbell.com</a>
<a href="http://www.sixbell.com" target="_blank" style="font-family:monospace">http://www.sixbell.com</a></pre>
</div>
_______________________________________________<br>
Kamailio (SER) - Users Mailing List<br>
<a href="mailto:sr-users@lists.kamailio.org" target="_blank">sr-users@lists.kamailio.org</a><br>
<a href="https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users" rel="noreferrer" target="_blank">https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users</a><br>
</blockquote></div></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div>Regards,</div><div><br></div>David Villasmil<div>email: <a href="mailto:david.villasmil.work@gmail.com" target="_blank">david.villasmil.work@gmail.com</a></div><div>phone: +34669448337</div></div></div>