<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
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<p>Hello,</p>
<p>there is no call at that moment, it is a routing-in-progress for
the initial INVITE. The proxy can cancel the outgoing branch that
returned the 183, send to another target address (e.g., call
hunting scenario) which comes back with another 183 and different
to-tag, or if the second target does not send any reply, then
proxy generates itself a 408 reply -- just to give an example of a
possible valid scenario.</p>
<p>So, the To-tag is used to identify requests within an established
dialog or to terminate a proxy-created branch in early phase. It
is not used to match the reply for initial INVITE transaction --
for that purpose the branch parameter of first via should be used
by calling UA.</p>
<p>A call is terminated by a BYE and there to-tag matters indeed.
But a transaction is not identified by using to-tag.<br>
</p>
<p>Cheers,<br>
Daniel<br>
</p>
<div class="moz-cite-prefix">On 23.07.20 14:41, Gerry | Rigatta
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:8C8DA54E-EE63-481C-9953-3409DEE4A68D@rigatta.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
Hi Daniel,
<div class=""><br class="">
</div>
<div class="">thanks for looking into this.<br class="">
<div class=""><br class="">
</div>
<div class="">The initial INVITE does not have a to-tag but
there is an intermediate session progress with a to-tag. See
grep below.</div>
<div class=""><br class="">
</div>
<div class="">The RFC does not distinguish between established
or provisional dialogs when it comes to the handling of the
to-tags. If there is a to-tag it must not be changed by the
Proxy. Clearly that must be so because the to-tag is used by
the UAC to identify the call. </div>
<div class=""><br class="">
</div>
<div class="">Best Gerry</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<div class="">IP addresses are changed in below dialog for
security reasons</div>
<div class=""><br class="">
</div>
<div class="">
<div class="">U 7.7.23.109:5060 -> 11.22.17.24:5060 #5</div>
<div class=""> INVITE <a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>
SIP/2.0..Max-Forwards: 19.</div>
<div class=""> .P-Asserted-Identity: <a
href="tel:+4867777777..Via:" class=""
moz-do-not-send="true">tel:+4867777777..Via:</a>
SIP/2.0/UDP 7.7.23.109:5060</div>
<div class=""> ;rport;branch=z9hG4bK1682611991..From:
"004867777777" <<a href="sip:004867777777@7" class=""
moz-do-not-send="true">sip:004867777777@7</a></div>
<div class=""> 8.47.203.109>;tag=540342132..To: <<a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a></div>
<div class=""> >..Call-ID: <a
href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
INVITE..User-Agent: nulltech.</div>
<div class=""> .Contact: <<a
href="sip:004867777777@7.7.23.109:5060" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.109:5060</a>>..Allow:
ACK, INVITE, BYE, </div>
<div class=""> CANCEL, REGISTER, REFER, OPTIONS, PRACK,
INFO..Supported: 100rel..Content-T</div>
<div class=""> ype: application/sdp..Content-Length:
209....v=0..o=yate 1595505273 1595505</div>
<div class=""> 273 IN IP4 7.7.23.109..s=SIP Call..c=IN IP4
7.7.23.109..t=0 0..m=audi</div>
<div class=""> o 28610 RTP/AVP 8 0 101..a=rtpmap:8
PCMA/8000..a=rtpmap:0 PCMU/8000..a=rtpm</div>
<div class=""> ap:101 telephone-event/8000..
</div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 7.7.23.109:5060 #6</div>
<div class=""> SIP/2.0 100 trying -- your call is important
to us..Via: SIP/2.0/UDP 78.47.</div>
<div class="">
203.109:5060;rport=5061;branch=z9hG4bK1682611991;received=7.7.23.109..Fr</div>
<div class=""> om: "004867777777" <<a
href="sip:004867777777@7.7.23.109" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<s</div>
<div class=""> ip:<a
href="mailto:111100791456321475@13.23.9.94" class=""
moz-do-not-send="true">111100791456321475@13.23.9.94</a>:5060>..Call-ID:
<a href="mailto:1279305029@7.7.23.10" class=""
moz-do-not-send="true">1279305029@7.7.23.10</a></div>
<div class=""> 9..CSeq: 1 INVITE..Server: kamailio (5.2.3
(x86_64/linux))..Content-Length:</div>
<div class=""> 0....
</div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 13.23.9.94:5060 #7</div>
<div class=""> INVITE <a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>
SIP/2.0..Record-Route: <si</div>
<div class=""> p:11.22.17.24:5060;lr=on>..Max-Forwards:
18..P-Asserted-Identity: <a href="tel:+" class=""
moz-do-not-send="true">tel:+</a></div>
<div class=""> 4867777777..Via: SIP/2.0/UDP
11.22.17.24:5060;branch=z9hG4bK58d4.f1e37</div>
<div class=""> b7feb047b6707c5fb8a298d36fc.0..Via:
SIP/2.0/UDP 7.7.23.109:5060;received</div>
<div class="">
=7.7.23.109;rport=5061;branch=z9hG4bK1682611991..From:
"004867777777" <</div>
<div class=""> <a href="sip:004867777777@7.7.23.109"
class="" moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<<a href="sip:111100791456321475" class=""
moz-do-not-send="true">sip:111100791456321475</a></div>
<div class=""> @13.23.9.94:5060>..Call-ID: <a
href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
INVITE..Us</div>
<div class=""> er-Agent: nulltech..Contact: <<a
href="sip:004867777777@7.7.23.109:5060" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.109:5060</a>>..Allow:</div>
<div class=""> ACK, INVITE, BYE, CANCEL, REGISTER, REFER,
OPTIONS, PRACK, INFO..Supported</div>
<div class=""> : 100rel..Content-Type:
application/sdp..Content-Length: 209....v=0..o=yate</div>
<div class=""> 1595505273 1595505273 IN IP4
7.7.23.109..s=SIP Call..c=IN IP4 7.7.23</div>
<div class=""> .109..t=0 0..m=audio 28610 RTP/AVP 8 0
101..a=rtpmap:8 PCMA/8000..a=rtpmap:</div>
<div class=""> 0 PCMU/8000..a=rtpmap:101
telephone-event/8000.. </div>
<div class="">#</div>
<div class="">U 13.23.9.94:5060 -> 11.22.17.24:5060 #8</div>
<div class=""> SIP/2.0 100 Trying..Via: SIP/2.0/UDP
11.22.17.24:5060;branch=z9hG4bK58d</div>
<div class="">
4.f1e37b7feb047b6707c5fb8a298d36fc.0;received=11.22.17.24..Via:
SIP/2.0</div>
<div class=""> /UDP
7.7.23.109:5060;received=7.7.23.109;rport=5061;branch=z9hG4bK168</div>
<div class=""> 2611991..Record-Route: <<a
href="sip:11.22.17.24:5060;lr=on" class=""
moz-do-not-send="true">sip:11.22.17.24:5060;lr=on</a>>..From:
"00371673360</div>
<div class=""> 58" <<a href="sip:004867777777@7.7.23.109"
class="" moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<<a href="sip:1111007914563" class=""
moz-do-not-send="true">sip:1111007914563</a></div>
<div class=""> <a href="mailto:21475@13.23.9.94" class=""
moz-do-not-send="true">21475@13.23.9.94</a>:5060>..Call-ID:
<a href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
INVIT</div>
<div class=""> E..User-Agent: Ravetel SIP proxy..Allow:
INVITE, ACK, CANCEL, OPTIONS, BYE,</div>
<div class=""> REFER, SUBSCRIBE, NOTIFY, INFO..Supported:
replaces..Contact: <<a href="sip:1111007" class=""
moz-do-not-send="true">sip:1111007</a></div>
<div class=""> <a href="mailto:91456321475@13.23.9.94"
class="" moz-do-not-send="true">91456321475@13.23.9.94</a>:5060>..Content-Length:
0.... </div>
<div class="">#</div>
<div class="">U 13.23.9.94:5060 -> 11.22.17.24:5060 #9</div>
<div class=""> SIP/2.0 183 Session Progress..Via: SIP/2.0/UDP
11.22.17.24:5060;branch=</div>
<div class="">
z9hG4bK58d4.f1e37b7feb047b6707c5fb8a298d36fc.0;received=11.22.17.24..Vi</div>
<div class=""> a: SIP/2.0/UDP
7.7.23.109:5060;received=7.7.23.109;rport=5061;branch=</div>
<div class=""> z9hG4bK1682611991..Record-Route: <<a
href="sip:11.22.17.24:5060;lr=on" class=""
moz-do-not-send="true">sip:11.22.17.24:5060;lr=on</a>>..From:
"0</div>
<div class=""> 04867777777" <<a
href="sip:004867777777@7.7.23.109" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<<a href="sip:103" class="" moz-do-not-send="true">sip:103</a></div>
<div class=""> <a href="mailto:000791456321475@13.23.9.94"
class="" moz-do-not-send="true">000791456321475@13.23.9.94</a>:5060>;tag=as6d86b4e8..Call-ID:
1279305029@78.</div>
<div class=""> 47.203.109..CSeq: 1 INVITE..User-Agent:
Ravetel SIP proxy..Allow: INVITE, A</div>
<div class=""> CK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE,
NOTIFY, INFO..Supported: replac</div>
<div class=""> es..Contact: <<a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>>..Content-Type:
app</div>
<div class=""> lication/sdp..Content-Length:
235....v=0..o=root 714 714 IN IP4 136.243.29.</div>
<div class=""> 94..s=session..c=IN IP4 13.23.9.94..t=0
0..m=audio 10454 RTP/AVP 8 0 101</div>
<div class=""> ..a=rtpmap:8 PCMA/8000..a=rtpmap:0
PCMU/8000..a=rtpmap:101 telephone-event/</div>
<div class=""> 8000..a=fmtp:101
0-16..a=ptime:20..a=sendrecv.. </div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 7.7.23.109:5060 #10</div>
<div class=""> SIP/2.0 183 Session Progress..Via: SIP/2.0/UDP
7.7.23.109:5060;received=</div>
<div class="">
7.7.23.109;rport=5061;branch=z9hG4bK1682611991..Record-Route:
<<a href="sip:116.2" class="" moz-do-not-send="true">sip:116.2</a></div>
<div class=""> 02.187.204:5060;lr=on>..From:
"004867777777" <<a href="sip:004867777777@7.7.23"
class="" moz-do-not-send="true">sip:004867777777@7.7.23</a>.</div>
<div class=""> 109>;tag=540342132..To: <<a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>>;tag=as6</div>
<div class=""> d86b4e8..Call-ID: <a
href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
INVITE..User-Agent: Ravet</div>
<div class="">el SIP proxy..Allow: INVITE, ACK, CANCEL,
OPTIONS, BYE, REFER, SUBSCRIBE,</div>
<div class=""> NOTIFY, INFO..Supported: replaces..Contact:
<<a href="sip:111100791456321475@136.24" class=""
moz-do-not-send="true">sip:111100791456321475@136.24</a></div>
<div class=""> 3.29.94:5060>..Content-Type:
application/sdp..Content-Length: 235....v=0..o</div>
<div class=""> =root 714 714 IN IP4
13.23.9.94..s=session..c=IN IP4 13.23.9.94..t=0 </div>
<div class=""> 0..m=audio 10454 RTP/AVP 8 0 101..a=rtpmap:8
PCMA/8000..a=rtpmap:0 PCMU/800</div>
<div class=""> 0..a=rtpmap:101
telephone-event/8000..a=fmtp:101 0-16..a=ptime:20..a=sendre</div>
<div class=""> cv..
</div>
<div class="">#</div>
<div class=""> </div>
<div class="">U 13.23.9.94:5060 -> 11.22.17.24:5060 #39</div>
<div class=""> SIP/2.0 503 Service Unavailable..Via:
SIP/2.0/UDP 11.22.17.24:5060;bran</div>
<div class="">
ch=z9hG4bK58d4.f1e37b7feb047b6707c5fb8a298d36fc.0;received=11.22.17.24.</div>
<div class=""> .Via: SIP/2.0/UDP
7.7.23.109:5060;received=7.7.23.109;rport=5061;bran</div>
<div class=""> ch=z9hG4bK1682611991..From: "004867777777"
<<a href="sip:004867777777@7.7.23.10" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.10</a></div>
<div class=""> 9>;tag=540342132..To: <<a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>>;tag=as6d8</div>
<div class=""> 6b4e8..Call-ID: <a
href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
INVITE..User-Agent: Ravet</div>
<div class=""> el SIP proxy..Allow: INVITE, ACK, CANCEL,
OPTIONS, BYE, REFER, SUBSCRIBE, N</div>
<div class=""> OTIFY, INFO..Supported:
replaces..X-Asterisk-HangupCause: Call Rejected..X-</div>
<div class=""> Asterisk-HangupCauseCode: 21..Content-Length:
0.... </div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 13.23.9.94:5060 #40</div>
<div class=""> ACK <a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>
SIP/2.0..Max-Forwards: 18..Vi</div>
<div class=""> a: SIP/2.0/UDP
11.22.17.24:5060;branch=z9hG4bK58d4.f1e37b7feb047b6707c5</div>
<div class=""> fb8a298d36fc.0..From: "004867777777" <<a
href="sip:004867777777@7.7.23.109" class=""
moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag</div>
<div class=""> =540342132..To: <<a
href="sip:111100791456321475@13.23.9.94:5060" class=""
moz-do-not-send="true">sip:111100791456321475@13.23.9.94:5060</a>>;tag=as6d86b4e8.</div>
<div class=""> .Call-ID: <a
href="mailto:1279305029@7.7.23.109" class=""
moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq: 1
ACK..Content-Length: 0.... </div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 7.7.23.109:5060 #41</div>
<div class=""> SIP/2.0 500 Service Unavailable..Via:
SIP/2.0/UDP 7.7.23.109:5060;rport=</div>
<div class="">
5061;branch=z9hG4bK1682611991;received=7.7.23.109..From:
"004867777777"</div>
<div class=""> <<a href="sip:004867777777@7.7.23.109"
class="" moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<<a href="sip:1111007914563214" class=""
moz-do-not-send="true">sip:1111007914563214</a></div>
<div class=""> <a href="mailto:75@13.23.9.94" class=""
moz-do-not-send="true">75@13.23.9.94</a>:5060>;tag=95329101123423eab1637e9ad490b3a6-9d3c..Call-ID: </div>
<div class=""> <a href="mailto:1279305029@7.7.23.109"
class="" moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq:
1 INVITE..Server: kamailio (5.2.3 (x86_64/l</div>
<div class=""> inux))..Content-Length: 0....
</div>
<div class="">#</div>
<div class="">U 11.22.17.24:5060 -> 7.7.23.109:5060 #42</div>
<div class=""> SIP/2.0 500 Service Unavailable..Via:
SIP/2.0/UDP 7.7.23.109:5060;rport=</div>
<div class="">
5061;branch=z9hG4bK1682611991;received=7.7.23.109..From:
"004867777777"</div>
<div class=""> <<a href="sip:004867777777@7.7.23.109"
class="" moz-do-not-send="true">sip:004867777777@7.7.23.109</a>>;tag=540342132..To:
<<a href="sip:1111007914563214" class=""
moz-do-not-send="true">sip:1111007914563214</a></div>
<div class=""> <a href="mailto:75@13.23.9.94" class=""
moz-do-not-send="true">75@13.23.9.94</a>:5060>;tag=95329101123423eab1637e9ad490b3a6-9d3c..Call-ID: </div>
<div class=""> <a href="mailto:1279305029@7.7.23.109"
class="" moz-do-not-send="true">1279305029@7.7.23.109</a>..CSeq:
1 INVITE..Server: kamailio (5.2.3 (x86_64/l</div>
<div class=""> inux))..Content-Length: 0....
</div>
<div class="">#</div>
</div>
<div class=""><br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On 23 Jul 2020, at 10:51, Daniel-Constantin
Mierla <<a href="mailto:miconda@gmail.com" class=""
moz-do-not-send="true">miconda@gmail.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" class="">
<div class="">
<p class="">Did the initial INVITE received the 200ok,
the call is connected and this is the case of a
re-INVITE? In such case the dialog has to be
terminated by a BYE.</p>
<p class="">If the call is not established, so it is
between initial INVITE and no 200ok was received,
then the INVITE request did not contain the To-tag.
And what is done by Kamailio is valid as per email
responses so far.<br class="">
</p>
<p class="">Maybe you can just send the ngrep output
with all sip requests/replies for this case and we
can see exactly which scenario you talk about.</p>
<p class="">Cheers,<br class="">
Daniel<br class="">
</p>
<div class="moz-cite-prefix">On 23.07.20 09:41, Gerry
| Rigatta wrote:<br class="">
</div>
<blockquote type="cite"
cite="mid:CA04FBF6-6916-452E-A574-D7B9E9158A20@rigatta.com"
class="">
<meta http-equiv="Content-Type" content="text/html;
charset=UTF-8" class="">
<div class="">
<blockquote type="cite" class="">
<div class="">
<p class="">Indeed, at this stage there is no
dialog established and there can be many
To-tags in 1xx provisional responses (eg, a
parallel forking scenario) -- the to-tag of
the dialog has to be taken from 200ok.</p>
</div>
</blockquote>
</div>
<div class="">As far as I read this is not correct.
Also a provisional dialog is a dialog according to
RFC3261. Only in the case that the request did not
contain a to-tag the provisional messages may
insert their own to-tags:</div>
<div class=""><br class="">
</div>
<div class="">
<pre class="newpage">"1xx and 2xx responses may be involved in the establishment of
dialogs. When a request does not contain a To tag, the To tag
in the response is used by the UAC to distinguish multiple
responses to a dialog creating request. A proxy MUST NOT
insert a tag into the To header field of a 1xx or 2xx response
if the request did not contain one. A proxy MUST NOT modify
the tag in the To header field of a 1xx or 2xx response.”</pre>
<pre class="newpage"><a href="https://tools.ietf.org/html/rfc3261#page-111" class="" moz-do-not-send="true">https://tools.ietf.org/html/rfc3261#page-111</a></pre>
</div>
<div class=""><br class="">
</div>
<div class="">In any case, this bug is not a about
provisional messages. The 500 message terminates
the dialog for the UAC (yate) and the UAC needs to
be able to identify it. An UAC identifies the
dialog by the call-id, local tag and remote tag.</div>
<div class=""><br class="">
</div>
<div class="">
<blockquote type="cite" class="">
<div class="">
<blockquote type="cite"
cite="mid:CAFZQphzM=C--zqrSSHfGvJSusWZaytM80Yosbuhhc6sBesvrZg@mail.gmail.com"
class="">
<div class="">
<div class="gmail_quote">
<blockquote class="gmail_quote"
style="margin: 0px 0px 0px 0.8ex;
border-left-width: 1px;
border-left-style: solid;
border-left-color: rgb(204, 204, 204);
padding-left: 1ex;">
<div link="blue" vlink="purple"
class="" lang="DE">
<div
class="m_-5300728039720019352WordSection1">
<div class="">
<div class="">
<h2 class=""
style="margin-left: 35.4pt;"><a
href="https://tools.ietf.org/html/rfc3261#section-12" target="_blank"
moz-do-not-send="true"
class=""><span class=""><span
class=""
style="font-family:
Arial, sans-serif;">12</span></span><span
class=""></span></a><span
class=""></span><span
class=""
style="font-family: Arial,
sans-serif;"> Dialogs</span></h2>
<h2 class=""
style="margin-left: 35.4pt;"><span
class=""
style="font-family: Arial,
sans-serif;">A dialog is
identified at each UA with
a dialog ID, which
consists of a Call-ID
value, a local tag and a
remote tag…"</span></h2>
</div>
</div>
</div>
</div>
</blockquote>
</div>
</div>
</blockquote>
</div>
</blockquote>
</div>
<div class=""><br class="">
</div>
<div class="">
<div class=""><br class="">
<blockquote type="cite" class="">
<div class="">On 23 Jul 2020, at 10:07,
Daniel-Constantin Mierla <<a
href="mailto:miconda@gmail.com" class=""
moz-do-not-send="true">miconda@gmail.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<meta http-equiv="Content-Type"
content="text/html; charset=UTF-8"
class="">
<div class="">
<p class="">Indeed, at this stage there is
no dialog established and there can be
many To-tags in 1xx provisional
responses (eg, a parallel forking
scenario) -- the to-tag of the dialog
has to be taken from 200ok.</p>
<p class="">This parameter is probably to
have a shortcut of doing:</p>
<p class="">failure_route[REMAP503] {</p>
<p class=""> if(t_check_status("503")) {</p>
<p class=""> t_reply("500", "Server
error");<br class="">
exit;</p>
<p class="">}</p>
<p class="">Being like the server
application is generating the 500 (so
using own tag), instead of forwarding
the 503. Not a bug, but if anyone is
willing to add an option to allow
re-using the to-tag from received reply,
I am fine with it.</p>
<p class="">Anyhow, even if this would be
fixed, I am wondering how yate is going
to work in parallel/serial forking
scenarios where different to-tags flow
for a while and the final failure
response can have any to-tag, including
a new one (e.g., from a device not
sending any 1xx or again from kamailio
(e.g., when last target doesn't reply at
all)).</p>
<p class="">Cheers,<br class="">
Daniel<br class="">
</p>
<div class="moz-cite-prefix">On 23.07.20
06:08, M S wrote:<br class="">
</div>
<blockquote type="cite"
cite="mid:CAFZQphzM=C--zqrSSHfGvJSusWZaytM80Yosbuhhc6sBesvrZg@mail.gmail.com"
class="">
<meta http-equiv="content-type"
content="text/html; charset=UTF-8"
class="">
<div class="">
<div dir="auto" class="">The SIP code
503 is tricky in the sense that i
can indicate either server
maintenance or server overload. In
both cases it can send Retry-After
header and any subsequent requests
from same source are ignored for the
duration of Retry-After interval.
[1].</div>
</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">Additionally
RFC3261 and RFC3263 define that
transport failures (generally due to
fatal ICMP errors in UDP and
connection failures in TCP) should be
treated as 503 response. [2].</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">So in all
above cases, it is most likely that
dialog does not establishes at all and
503 response is treated similar to
stateless response. Therefore, a
to-tag can be added/replaced before
sending it to UAC.</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">Theoretically,
kamailio should check and use to-tag
from 503 response when converting it
to 500 response and only create new
to-tag if it is absent.</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">References:</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">
<div class="">[1] <a
href="https://tools.ietf.org/html/rfc3261#section-21.5.4"
moz-do-not-send="true" class="">https://tools.ietf.org/html/rfc3261#section-21.5.4</a></div>
<div dir="auto" class=""><br class="">
</div>
<div class="">[2] <a
href="https://tools.ietf.org/html/draft-hilt-sip-correction-503-01#section-4"
moz-do-not-send="true" class="">https://tools.ietf.org/html/draft-hilt-sip-correction-503-01#section-4</a></div>
<br class="">
</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class="">Hope
this helps.</div>
<div dir="auto" class=""><br class="">
</div>
<div dir="auto" class=""><br class="">
</div>
<div class=""><br class="">
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On
Wed, 22 Jul 2020 at 21:08, Henning
Westerholt <<a
href="mailto:hw@skalatan.de"
moz-do-not-send="true" class="">hw@skalatan.de</a>>
wrote:<br class="">
</div>
<blockquote class="gmail_quote"
style="margin:0 0 0
.8ex;border-left:1px #ccc
solid;padding-left:1ex">
<div link="blue" vlink="purple"
class="" lang="DE">
<div
class="m_-5300728039720019352WordSection1">
<p class="MsoNormal"><span
class="">Hello,</span></p>
<div class=""><span class=""> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">Apparently,
this is the way the code
works:</span></p>
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">t_reply.c:</span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">
if (relayed_code==503
&&
tm_remap_503_500){</span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">
/* replace a final 503
with a 500:</span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">
*
generate a "FAKE" reply
and a new to_tag (for
easier</span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">
* debugging)*/</span></p>
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">Lets
see if maybe others can
comment as well. Otherwise
you could just open an
issue on our tracker, it
is probably not that hard
to change this.</span></p>
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">Cheers,</span></p>
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">Henning</span></p>
<div class="">
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"><span
class="" lang="EN-GB">--
</span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">Henning
Westerholt – </span><span
class=""><a
href="https://skalatan.de/blog/"
target="_blank"
moz-do-not-send="true"
class=""><span
style="color:#0563c1"
class=""
lang="EN-GB">https://skalatan.de/blog/</span></a></span><span
class="" lang="EN-GB"></span></p>
<p class="MsoNormal"><span
class="" lang="EN-GB">Kamailio
services – </span><span
class=""><a
href="https://gilawa.com/"
target="_blank"
moz-do-not-send="true"
class=""><span
style="color:#0563c1"
class=""
lang="EN-GB">https://gilawa.com</span></a></span><span
class=""> <span
class="" lang="EN-GB"></span></span></p>
</div>
<div class=""><span class=""
lang="EN-GB"> </span><br
class="webkit-block-placeholder">
</div>
<div class="">
<div
style="border:none;border-top:solid
#e1e1e1
1.0pt;padding:3.0pt 0cm
0cm 0cm" class="">
<p class="MsoNormal"
style="margin-left:35.4pt"><b
class="">From:</b>
sr-users <<a
href="mailto:sr-users-bounces@lists.kamailio.org"
target="_blank"
moz-do-not-send="true"
class="">sr-users-bounces@lists.kamailio.org</a>>
<b class="">On Behalf Of
</b>Gerry | Rigatta<br
class="">
<b class="">Sent:</b>
Wednesday, July 22, 2020
8:58 PM<br class="">
<b class="">To:</b>
Kamailio (SER) - Users
Mailing List <<a
href="mailto:sr-users@lists.kamailio.org"
target="_blank"
moz-do-not-send="true"
class="">sr-users@lists.kamailio.org</a>><br
class="">
<b class="">Subject:</b>
[SR-Users] bug ?
remap_503_500 breaks
dialogs</p>
</div>
</div>
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
<p class="MsoNormal"
style="margin-left:35.4pt">Hi,</p>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
<div class="">
<p class="MsoNormal"
style="margin-left:35.4pt">I
am using Kamailio 5.2. </p>
</div>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
<div class="">
<p class="MsoNormal"
style="margin-left:35.4pt">Apparently
the remapping of 503 to
500 codes in the tm module
does also change the
to-tag. This behaviour
breaks dialogs with yate
and therefore calls hang
and the 503 remains
unacknowledged. After
disabling the 503 to 500
remapping with
modparam("tm",
"remap_503_500", 0) all
works fine again.</p>
</div>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
<div class="">
<p class="MsoNormal"
style="margin-left:35.4pt">Changing
the to-tag in a dialog
seems to contradict
RFC3261, or do I see this
wrongly?</p>
</div>
<div class="">
<h2
style="margin-left:35.4pt"
class=""><a
name="m_-5300728039720019352_section-12"
moz-do-not-send="true"
class=""></a><a
href="https://tools.ietf.org/html/rfc3261#section-12"
target="_blank"
moz-do-not-send="true"
class=""><span class=""><span
style="font-family:"Arial",sans-serif" class="">12</span></span><span
class=""></span></a><span
class=""></span><span
style="font-family:"Arial",sans-serif"
class=""> Dialogs</span></h2>
<h2
style="margin-left:35.4pt"
class=""><span
style="font-family:"Arial",sans-serif"
class="">A dialog is
identified at each UA
with a dialog ID, which
consists of a Call-ID
value, a local tag and a
remote tag…"</span></h2>
</div>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
<div class="">
<p class="MsoNormal"
style="margin-left:35.4pt">Thanks
for looking into this.</p>
</div>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
<div class="">
<p class="MsoNormal"
style="margin-left:35.4pt">Gerry</p>
</div>
<div class="">
<div style="margin-left:
35.4pt;" class=""> <br
class="webkit-block-placeholder">
</div>
</div>
</div>
</div>
_______________________________________________<br class="">
Kamailio (SER) - Users Mailing
List<br class="">
<a
href="mailto:sr-users@lists.kamailio.org"
target="_blank"
moz-do-not-send="true" class="">sr-users@lists.kamailio.org</a><br
class="">
<a
href="https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users"
rel="noreferrer" target="_blank"
moz-do-not-send="true" class="">https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users</a><br
class="">
</blockquote>
</div>
</div>
<br class="">
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
Kamailio (SER) - Users Mailing List
<a class="moz-txt-link-abbreviated" href="mailto:sr-users@lists.kamailio.org" moz-do-not-send="true">sr-users@lists.kamailio.org</a>
<a class="moz-txt-link-freetext" href="https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users" moz-do-not-send="true">https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
Daniel-Constantin Mierla -- <a class="moz-txt-link-abbreviated" href="http://www.asipto.com/" moz-do-not-send="true">www.asipto.com</a>
<a class="moz-txt-link-abbreviated" href="http://www.twitter.com/miconda" moz-do-not-send="true">www.twitter.com/miconda</a> -- <a class="moz-txt-link-abbreviated" href="http://www.linkedin.com/in/miconda" moz-do-not-send="true">www.linkedin.com/in/miconda</a>
Funding: <a class="moz-txt-link-freetext" href="https://www.paypal.me/dcmierla" moz-do-not-send="true">https://www.paypal.me/dcmierla</a></pre>
</div>
_______________________________________________<br class="">
Kamailio (SER) - Users Mailing List<br
class="">
<a href="mailto:sr-users@lists.kamailio.org"
class="" moz-do-not-send="true">sr-users@lists.kamailio.org</a><br
class="">
<a class="moz-txt-link-freetext"
href="https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users"
moz-do-not-send="true">https://lists.kamailio.org/cgi-bin/mailman/listinfo/sr-users</a><br
class="">
</div>
</blockquote>
</div>
<br class="">
</div>
</blockquote>
<pre class="moz-signature" cols="72">--
Daniel-Constantin Mierla -- <a class="moz-txt-link-abbreviated" href="http://www.asipto.com/" moz-do-not-send="true">www.asipto.com</a>
<a class="moz-txt-link-abbreviated" href="http://www.twitter.com/miconda" moz-do-not-send="true">www.twitter.com/miconda</a> -- <a class="moz-txt-link-abbreviated" href="http://www.linkedin.com/in/miconda" moz-do-not-send="true">www.linkedin.com/in/miconda</a>
Funding: <a class="moz-txt-link-freetext" href="https://www.paypal.me/dcmierla" moz-do-not-send="true">https://www.paypal.me/dcmierla</a></pre>
</div>
</div>
</blockquote>
</div>
<br class="">
</div>
</div>
</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>
Funding: <a class="moz-txt-link-freetext" href="https://www.paypal.me/dcmierla">https://www.paypal.me/dcmierla</a></pre>
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