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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Paul,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Sorry it this was unclear.<span
style='mso-spacerun:yes'> </span>I meant to say that I don’t think UA
should respond with ACK to provisional response (i.e. 100 Trying). I just
scanned through an RFC and did not see anywhere where it says provisional
responses should be <span class=SpellE>ACKed</span>. Also, I am unclear on why
UA changed CSEQ. <span class=GramE>Any ideas on that?</span><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Alex<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> <st1:PersonName
w:st="on">Java Rockx</st1:PersonName> [mailto:javarockx@gmail.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, April 15, 2005 2:12
PM<br>
<b><span style='font-weight:bold'>To:</span></b> Alex Vishnev<br>
<b><span style='font-weight:bold'>Cc:</span></b> serusers@lists.iptel.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Serusers] Another
Looping Question</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Thanks Alex.<br>
<br>
So just to be clear, are you saying this:<br>
<br>
1) When ser receives an INVITE it does not need to reply with "100
Trying"<br>
<br>
2) When the SER tm module sends back the 100 Trying, the SIP UA should not be
changing the Cseq header?<br>
<br>
Regards,<br>
Paul<o:p></o:p></span></font></p>
<div>
<p class=MsoNormal><span class=gmailquote><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>On 4/15/05, <b><span style='font-weight:bold'>Alex
Vishnev</span></b> <<a href="mailto:avishnev@optonline.net">avishnev@optonline.net</a>>
wrote:</span></font></span><o:p></o:p></p>
<div>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'>Paul,</span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'> </span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'>It looks like UA ACK 100 Trying. First of all I don't believe
this is needed. Second of all, it changes CSEQ from 101 INVITE to 100. I think
that's not valid at all. </span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'>HTH</span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'> </span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'>Alex</span></font><o:p></o:p></p>
<p><font size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:
Arial;color:navy'> </span></font><o:p></o:p></p>
<div>
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face="Times New Roman"><span style='font-size:12.0pt'>
<hr size=2 width="100%" align=center>
</span></font></div>
<p><b><font size=2 face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma;
font-weight:bold'>From:</span></font></b><font size=2 face=Tahoma><span
style='font-size:10.0pt;font-family:Tahoma'> <a
href="mailto:serusers-bounces@iptel.org" target="_blank">serusers-bounces@lists.iptel.org</a>
[mailto:<a href="mailto:serusers-bounces@lists.iptel.org" target="_blank">
serusers-bounces@lists.iptel.org</a>] <b><span style='font-weight:bold'>On Behalf Of </span></b><st1:PersonName
w:st="on">Java Rockx</st1:PersonName><br>
<b><span style='font-weight:bold'>Sent:</span></b> Friday, April 15, 2005 10:46
AM<br>
<b><span style='font-weight:bold'>To:</span></b> <a
href="mailto:serusers@lists.iptel.org" target="_blank">serusers@lists.iptel.org</a><br>
<b><span style='font-weight:bold'>Subject:</span></b> [Serusers] Another
Looping Question</span></font><o:p></o:p></p>
</div>
<div><span id="q_10346f0fc05c4106_1">
<p><font size=3 face="Times New Roman"><span style='font-size:12.0pt'> <o:p></o:p></span></font></p>
<p style='margin-bottom:12.0pt'><font size=3 face="Times New Roman"><span
style='font-size:12.0pt'>Hi All.<br>
<br>
Below is a snippet of an INVITE and you can see the usual "trying - your
call is important to us" in the dialog. Anyhow, for some reason SER
occasionally attempts to sent the ACK to itself, which causes a looping
condition. The last ACK shown is the start of the looping condition.<br>
<br>
It only happens on occasion. SER should have consumed the ACK rather than
attempted to forward it.<br>
<br>
Can anyone explain this?<br>
<br>
Regards,<br>
Paul<br>
<br>
IP Legend<br>
-------------------<br>
<a href="http://10.3.0.221" target="_blank">10.3.0.221</a> - SER (behind a
Cisco 3600 so ALG rewrote the IPs)<br>
<a href="http://69.36.46.178" target="_blank">69.36.46.178</a> - NATed SIP UA<br>
<br>
U 2005/04/15 02:19:16.252614 <a href="http://69.35.46.178:5060" target="_blank">69.35.46.178:5060</a>
-> <a href="http://10.3.0.221:5060" target="_blank">10.3.0.221:5060</a><br>
INVITE <a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>
SIP/2.0.<br>
Via: SIP/2.0/UDP <a href="http://192.168.1.102:5060" target="_blank">192.168.1.102:5060</a>;branch=z9hG4bK3915905414.<br>
From: Test User <<a href="mailto:sip:3215591439@sipdev.mycompany.net"
target="_blank">sip:3215591439@sipdev.mycompany.net</a>>;tag=1465261089.<br>
To: <<a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>>.<br>
Call-ID: <a href="mailto:2671219156@192.168.1.102" target="_blank">2671219156@192.168.1.102</a>.<br>
CSeq: 101 INVITE.<br>
Contact: <sip:3215591439@192.168.1.102:5060>.<br>
Proxy-Authorization: Digest username="3215591439", realm="<a
href="http://sipdev.mycompany.net" target="_blank">sipdev.mycompany.net</a>",
nonce="425f5e0de25efdb3f5a6125dcf2147bf30fe9177", uri="<a
href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net
</a>", response="61996c3bdc10990fec7e245751777516",
algorithm=MD5, cnonce="ae02e47a3355bada49ce344c92f48587", qop=auth,
nc=00000002. max-forwards: 70.<br>
Allow: INVITE, ACK, CANCEL, BYE, REFER, NOTIFY.<br>
Content-Type: application/sdp.<br>
Content-Length: 180.<br>
.<br>
v=0.<br>
o=- 32014 3005 IN IP4 <a href="http://192.168.1.102" target="_blank">192.168.1.102</a>.<br>
s=-.<br>
c=IN IP4 <a href="http://192.168.1.102" target="_blank">192.168.1.102</a>.<br>
t=0 0.<br>
m=audio 13456 RTP/AVP 18 0 8 2 4 101.<br>
a=rtpmap:101 telephone-event/8000.<br>
a=fmtp:101 0-15.<br>
a=ptime:20.<br>
.<br>
<br>
#<br>
U 2005/04/15 02:19:16.276216 <a href="http://10.3.0.221:5060" target="_blank">10.3.0.221:5060</a>
-> <a href="http://69.35.46.178:5060" target="_blank">69.35.46.178:5060</a><br>
SIP/2.0 100 trying -- your call is important to us.<br>
Via: SIP/2.0/UDP <a href="http://192.168.1.102:5060" target="_blank">192.168.1.102:5060</a>;branch=z9hG4bK3915905414;rport=5060;received=<a
href="http://69.35.46.178" target="_blank"> 69.35.46.178</a>.<br>
From: Test User <<a href="mailto:sip:3215591439@sipdev.mycompany.net"
target="_blank">sip:3215591439@sipdev.mycompany.net</a>>;tag=1465261089.<br>
To: <<a href="mailto:sip:8187768080@sipdev.myvox.net" target="_blank">sip:8187768080@sipdev.myvox.net</a>>.<br>
Call-ID: <a href="mailto:2671219156@192.168.1.102" target="_blank">2671219156@192.168.1.102</a>.<br>
CSeq: 101 INVITE.<br>
Content-Length: 0.<br>
.<br>
<br>
#<br>
U 2005/04/15 02:19:16.792795 <a href="http://69.35.46.178:5060" target="_blank">69.35.46.178:5060</a>
-> <a href="http://10.3.0.221:5060" target="_blank">10.3.0.221:5060</a><br>
ACK <a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>
SIP/2.0.<br>
Via: SIP/2.0/UDP <a href="http://192.168.1.102:5060" target="_blank">192.168.1.102:5060</a>;branch=z9hG4bK3499714875.<br>
From: Test User <<a href="mailto:sip:3215591439@sipdev.mycompany.net"
target="_blank">sip:3215591439@sipdev.mycompany.net</a>>;tag=1465261089.<br>
To: <<a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>>;tag=cdbfe46960d7566fcbe09f199f2b328d.c2bb.<br>
Call-ID: <a href="mailto:2671219156@192.168.1.102" target="_blank">2671219156@192.168.1.102</a>.<br>
CSeq: 100 ACK.<br>
Content-Length: 0.<br>
.<br>
<br>
#<br>
U 2005/04/15 02:19:16.912146 <a href="http://10.3.0.221:5060" target="_blank">10.3.0.221:5060</a>
-> <a href="http://10.3.0.221:5060" target="_blank">10.3.0.221:5060</a><br>
ACK <a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>
SIP/2.0.<br>
Max-Forwards: 10.<br>
Record-Route: <sip:<a href="http://10.3.0.221" target="_blank">10.3.0.221</a>;ftag=1465261089;lr>.<br>
Via: SIP/2.0/UDP <a href="http://10.3.0.221" target="_blank">10.3.0.221</a>;branch=0.<br>
Via: SIP/2.0/UDP <a href="http://192.168.1.102:5060" target="_blank">192.168.1.102:5060</a>;received=<a
href="http://69.35.46.178" target="_blank"> 69.35.46.178</a>;branch=z9hG4bK3499714875.<br>
From: Test User <<a href="mailto:sip:3215591439@sipdev.mycompany.net"
target="_blank">sip:3215591439@sipdev.mycompany.net</a>>;tag=1465261089.<br>
To: <<a href="mailto:sip:8187768080@sipdev.mycompany.net" target="_blank">sip:8187768080@sipdev.mycompany.net</a>>;tag=cdbfe46960d7566fcbe09f199f2b328d.c2bb.<br>
Call-ID: <a href="mailto:2671219156@192.168.1.102" target="_blank">2671219156@192.168.1.102</a>.<br>
CSeq: 100 ACK.<br>
Content-Length: 0.<br>
P-hint: Local Destination.<o:p></o:p></span></font></p>
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