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<p class="MsoNormal"><span style="font-size:11.0pt">Bogdan,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Just as an update, this does not work. The match_dialog function must do loose routing on its own and even though I call remove_hf(“Route”) before match_dialog(), it still processes the Route header on the
incoming message. So match_dialog returns true, but the TH refactoring is not applied and $du is set to the IP from the incoming message’s Route header, which is my server.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Ben Newlin</span><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="color:black">From: </span></b><span style="color:black">Bogdan-Andrei Iancu <bogdan@opensips.org><br>
<b>Date: </b>Monday, August 1, 2016 at 7:13 AM<br>
<b>To: </b>"Newlin, Ben" <Ben.Newlin@inin.com>, OpenSIPS users mailling list <users@lists.opensips.org><br>
<b>Subject: </b>Re: [OpenSIPS-Users] Record-Route and Dialog topology_hiding()<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Times New Roman""><o:p> </o:p></span></p>
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<p class="MsoNormal"><tt><span style="font-size:10.0pt">Hi Ben,</span></tt><span style="font-size:10.0pt;font-family:"Courier New""><br>
<br>
<tt>I see your problem here. So, let's explore this:</tt><br>
<tt>1) for sending the call to carrier, on OpenSIPS, you do TH (with advertise) resulting in a Contact with the public IP of the SBC.</tt><br>
<tt>2) also, manually add a RR header with the private IP of OpenSIPS.</tt><br>
<tt>3) send call to SBC, which will add its own RR stuff.</tt><br>
<br>
<tt>Now, on the sequential request from Carrier, the RURI will contain the Contact of OpenSIPS (the pub IP of SBC), some Route hdrs due the SBC and the Route we added on OpenSIPS.</tt><br>
<tt>- when request gets to SBC, the SBC will do loose route, consume its Route headers, and it will use the next available Route which points to the priv IP of OpenSIPS (and it will not use the public IP in RURI for routing)</tt><br>
<tt>- requests gets to OpenSIPS, simply remove_hf() and Route headers (do not do any loose_route() as it is useless) and hit th_matching -> this will refactor the request (RURI, Contact, Route) for the leg on the other side -> this should be fine.</tt><br>
<br>
<tt>For the other direction (still sequential), you do th_matching on OpenSIPS and nothing more. This will send a request holding the Routes due the SBC, a Contact with the public IP and and RURI pointing probably to the carrier.</tt><br>
<br>
<tt>Shortly you do standard TH, but on outbound scenario, add a fake RR header to trick the SBC to route the sequential to your OpenSIPS.</tt><br>
<br>
<tt>Does it make sense ? </tt><br>
<br>
<br>
<tt>Regards,</tt><br>
<br>
</span><o:p></o:p></p>
<pre>Bogdan-Andrei Iancu<o:p></o:p></pre>
<pre>OpenSIPS Founder and Developer<o:p></o:p></pre>
<pre><a href="http://www.opensips-solutions.com">http://www.opensips-solutions.com</a><o:p></o:p></pre>
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<p class="MsoNormal">On 29.07.2016 18:05, Newlin, Ben wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Here is the scenario:</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">My servers are only listening on a private IP address. There is a public address on our SBC. I have a carrier that requires that the Contact IP address matches the public address we provided to them. So when
I do TH on my server I have to also do set_advertised_address to advertise the public address in the Contact header. Sequential requests use the Contact as the Request URI and the SBC is doing RR so all requests will come back through it. When the SBC receives
a sequential request it strips its Route headers and forwards to the Request URI (previous Contact URI). But that URI now points back to the SBC, so it cannot deliver the request. If my server could Record-Route the initial request with its private address,
the SBC would be able to route the request back to it.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Here is a trace of my scenario:
<a href="http://pastebin.com/x927mFtq">http://pastebin.com/x927mFtq</a>. I created it with SIPp so some endpoints are on the same IPs but with different ports. The public IP is 192.168.99.100, with port 7060 representing the PSTN carrier and port 5060 the SBC.
The private IP is 10.0.2.15, with port 5060 being the SBC again and port 6060 being my server. You can see that the ACK cannot be delivered correctly to my server with this configuration.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">The problem here stems from the fact that Topology Hiding should really be done at the edge of the network in order to be most effective. But my OpenSIPS server doesn’t sit on the Edge of the network, it is
behind an SBC. So TH is complicated by the fact that my OpenSIPS has no public IP of its own and must advertise the public IP of the SBC instead, but future requests must still be routable into the private network. I am really using TH to hide the two ends
of the call from each other, not to hide my internal network topology.</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"> </span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Ben Newlin</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
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<p class="MsoNormal"><b><span style="color:black">From: </span></b><span style="color:black">Bogdan-Andrei Iancu
<a href="mailto:bogdan@opensips.org"><bogdan@opensips.org></a><br>
<b>Date: </b>Friday, July 29, 2016 at 8:40 AM<br>
<b>To: </b>"Newlin, Ben" <a href="mailto:Ben.Newlin@inin.com"><Ben.Newlin@inin.com></a>, OpenSIPS users mailling list
<a href="mailto:users@lists.opensips.org"><users@lists.opensips.org></a><br>
<b>Subject: </b>Re: [OpenSIPS-Users] Record-Route and Dialog topology_hiding()</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Times New Roman \, serif ""> </span><o:p></o:p></p>
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<p class="MsoNormal"><tt><span style="font-size:10.0pt">Hi Ben,</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
</span><tt><span style="font-size:10.0pt">Sorry to disagree, but IMHO they do exclude one each other.
</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
</span><tt><span style="font-size:10.0pt">Adding RR to TH should not be seen as a way of fixing some broken TH scenarios (with advertise).</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
</span><tt><span style="font-size:10.0pt">So, let me try to understand what is not working for you. You do TH and advertise. In this case, normally, in the Contact headers generated by OpenSIPS (as a result of TH), it should be the TH interface, right ? What
exactly seems to be the problem ? do you have a trace to show the issues ?</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
</span><tt><span style="font-size:10.0pt">Regards,</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
<br>
</span><o:p></o:p></p>
<pre>Bogdan-Andrei Iancu<o:p></o:p></pre>
<pre>OpenSIPS Founder and Developer<o:p></o:p></pre>
<pre><a href="http://www.opensips-solutions.com">http://www.opensips-solutions.com</a><o:p></o:p></pre>
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<p class="MsoNormal">On 27.07.2016 16:05, Newlin, Ben wrote:<o:p></o:p></p>
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<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="font-size:11.0pt">I understand that normally you would not need RR with TH, but the two concepts are not mutually exclusive in SIP. As I said, I have a need to Record-Route the call on my server as I am advertising a different
address than I am listening on. This means that TH will populate the Contact header with the advertised address and if I cannot Record-Route with the actual address then I will not receive sequential requests.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black"> </span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:10.5pt;color:black">Ben Newlin</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
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<p class="MsoNormal"><b><span style="color:black">From: </span></b><span style="color:black">Bogdan-Andrei Iancu
<a href="mailto:bogdan@opensips.org"><bogdan@opensips.org></a><br>
<b>Date: </b>Wednesday, July 27, 2016 at 3:59 AM<br>
<b>To: </b>OpenSIPS users mailling list <a href="mailto:users@lists.opensips.org">
<users@lists.opensips.org></a>, "Newlin, Ben" <a href="mailto:Ben.Newlin@inin.com">
<Ben.Newlin@inin.com></a><br>
<b>Subject: </b>Re: [OpenSIPS-Users] Record-Route and Dialog topology_hiding()</span><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Times New Roman \, serif ""> </span><o:p></o:p></p>
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<p class="MsoNormal"><tt><span style="font-size:10.0pt">Hi Ben,</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
</span><tt><span style="font-size:10.0pt">As I mentioned in different thread, TH is not compatible with the RR mechanism. If you do TH, your OpenSIPS will act as and end point (from SIP perspective), so there will be no Route/RR headers at all. So no need to
do loose_route or so. You just do TH matching for the sequential requests and nothing more.</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
</span><tt><span style="font-size:10.0pt">Regards,</span></tt><span style="font-size:10.0pt;font-family:"Courier New \, serif ""><br>
<br>
<br>
<br>
</span><o:p></o:p></p>
<pre>Bogdan-Andrei Iancu<o:p></o:p></pre>
<pre>OpenSIPS Founder and Developer<o:p></o:p></pre>
<pre><a href="http://www.opensips-solutions.com">http://www.opensips-solutions.com</a><o:p></o:p></pre>
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<p class="MsoNormal">On 22.07.2016 16:48, Newlin, Ben wrote:<o:p></o:p></p>
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<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal"><span style="font-size:11.0pt">Hi,</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I am using the Dialog module with topology_hiding() in my server and I have a need to Record-Route the call on my server as I am advertising a different address than I am listening on. I have found what I
believe is an inconsistency in the handling of Record-Route within the Dialog topology_hiding functionality. The topology_hiding isn’t a true B2BUA, but it does set up different parameters for the incoming UAC and outgoing UAS sides of the call for the Via
headers, Record-Route and Route headers, and the Contact header(s).</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">The problem is that the record_route() and loose_route() functions operate on different sides of the call. The record_route() function will only add a Record-Route header to the outgoing UAS side of the call.
And since the record_route() function cannot be called from onreply_route, but is no way to add a Record-Route header to the UAC side of the call.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">On the other hand, the loose_route() function only operates on the incoming UAC side of the call and there is no way to perform loose_route() on the UAS side of the call.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">So there is a situation where Record-Route headers can only be added on the outgoing UAS side, but the associated Route headers can only be removed on the incoming UAC side (where they won’t exist since they
can’t be added) and any added headers on the UAS side cannot be processed properly due to the lack of loose_route.</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> </span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I can provide further information if this is unclear. It should be easily reproducible by attempting to use record_route in a topology_hiding scenario. The route is added to the outbound leg, but is not removed
by loose_route so the message is looped back every time.</span><o:p></o:p></p>
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<p class="MsoNormal" style="line-height:16.8pt;background:white"><b><span style="font-size:10.0pt;font-family:Arial;color:#155570">Ben Newlin</span></b><b><span style="font-size:10.0pt;font-family:Arial;color:#666666"> </span></b><span style="font-size:10.0pt;font-family:Arial;color:#666666">|
Sr Voice Network Engineer, PureCloud</span><o:p></o:p></p>
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<p class="MsoNormal" style="line-height:16.8pt;background:white"><span style="font-size:10.0pt;font-family:Arial;color:#666666">phone & fax +1.317.957.1009 | </span><span style="font-size:10.0pt;font-family:Arial;color:#0585A7"><a href="mailto:ben.newlin@inin.com">ben.newlin@inin.com</a> </span><o:p></o:p></p>
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<p class="MsoNormal" style="line-height:16.8pt;background:white"><span style="font-size:9.0pt;font-family:Arial;color:#666666;border:solid windowtext 1.0pt;padding:0in"><img border="0" width="196" height="21" id="_x0000_i1025" src="cid:Word%20Work%20File%20D_.jpg" alt="ge removed by sender."></span><o:p></o:p></p>
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<p class="MsoNormal" style="line-height:12.0pt;background:white"><span style="font-size:10.0pt;font-family:Arial;color:#0585A7"><a href="http://www.inin.com">www.inin.com</a></span><o:p></o:p></p>
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