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<p>Hello,</p>
<p>every SIP UA that sends out a request must add a Via header with
own address, not matter is the originating UA, intermediary SBC or
proxy. The SBC/B2BUA, remove incoming Via headers, but they add
one with onw address, otherwise routing of replies does not work.</p>
<p>Anyhow, if you need topology hiding for calls, look at topos or
topoh modules in Kamailio.</p>
<p>Cheers,<br>
Daniel<br>
</p>
<div class="moz-cite-prefix">On 13.07.21 10:08, Mojtaba wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CABVi_Ewgm-e43efd3E+Gi=ecZsEsdLDYDM0ss-_=h6Gf+_9Gnw@mail.gmail.com">
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<div>Hello there,</div>
<div>According to ,<a
href="https://lists.kamailio.org/pipermail/sr-users/2016-March/092058.html"
moz-do-not-send="true">https://lists.kamailio.org/pipermail/sr-users/2016-March/092058.html</a>,
which talked about B2BUA (just signalling) in Kamailio.<br>
</div>
<div>As i have experienced working with SEMS, freeswitch and
Kamailio while using B2BUA feature, Each of them have pros and
cons:</div>
<div>1- The sems is a light sip engine server with several
applications (like as sbc) for using b2bua. All incoming and
outgoing calls could go to sems server for doing b2bua like
this:</div>
<div><br>
</div>
<div>Incoming<=======>Kamailio<========>Sems<========>Kamailio<=======>outgoing</div>
<div><br>
</div>
<div>2- In sems, you could disable rtp realying. It forces sems
to work just as b2bua without anchoring RTP<br>
</div>
<div>3- Easy to use different active profiles in routing.</div>
<div>Just a couple of things there are in SEMS. For example,
the sems adds itself (local IP) in Via header, and it couldn't
be common in b2bua. like this:</div>
<div>.</div>
<div>.</div>
<div>.<br>
</div>
<div>INVITE <a href="mailto:sip%3A200@cloud.domain.com"
target="_blank" moz-do-not-send="true">sip:200@cloud.domain.com</a>;transport=UDP
SIP/2.0<br>
Via: SIP/2.0/UDP
10.10.10.200;branch=z9hG4bK2f53.07a3fd9edaa8c8d609ab2ac6b01a087f.0
<b>================================>Kamailio public IP</b><br>
<b>Via: SIP/2.0/UDP
127.0.0.1:5080;received=127.0.0.1;branch=z9hG4bKsPRMNast;rport=5080
===============================>private loopback sems ip</b><br>
From: <<a href="mailto:sip%3A100@cloud.domain.com"
target="_blank" moz-do-not-send="true">sip:100@cloud.domain.com</a>;transport=UDP>;tag=6FFDB493-60EABB3600016ECD-379F9700<br>
To: <<a href="mailto:sip%3A200@cloud.domain.com"
target="_blank" moz-do-not-send="true">sip:200@cloud.domain.com</a>;transport=UDP><br>
CSeq: 10 INVITE<br>
Call-ID: Y2M1ODQxNTZmMjdkZWZjN2U5MmMyYjBmN2Y2OGY1ODQ._leg2<br>
Route: <a class="moz-txt-link-rfc2396E" href="sip:mo@127.0.0.1:5060;lr"><sip:mo@127.0.0.1:5060;lr></a><br>
Max-Forwards: 69<br>
Allow: INVITE, ACK, CANCEL, BYE, NOTIFY, REFER, MESSAGE,
OPTIONS, INFO, SUBSCRIBE<br>
User-Agent: Z 3.3.25608 r25552<br>
Content-Type: application/sdp<br>
Contact: <a class="moz-txt-link-rfc2396E" href="sip:127.0.0.1:5080;transport=udp"><sip:127.0.0.1:5080;transport=udp></a><br>
Content-Length: 246</div>
<div>.</div>
<div>.</div>
<div>.</div>
<div>For this reason, Is there a way to avoid this issue? I know
it is possible to do this by using other modules like textops
and retransformation ?</div>
<div>
<div>And why in Kamailio, there is no b2bua module to perform
all b2bua functionality, yet? <br>
</div>
<div>Thanks with Best Regards.</div>
</div>
<div><br>
</div>
<br>
-- <br>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">--Mojtaba Esfandiari.S</div>
</div>
<br>
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</blockquote>
<pre class="moz-signature" cols="72">--
Daniel-Constantin Mierla -- <a class="moz-txt-link-abbreviated" href="http://www.asipto.com">www.asipto.com</a>
<a class="moz-txt-link-abbreviated" href="http://www.twitter.com/miconda">www.twitter.com/miconda</a> -- <a class="moz-txt-link-abbreviated" href="http://www.linkedin.com/in/miconda">www.linkedin.com/in/miconda</a></pre>
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