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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi all,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>is there a way to make freeswitch send a 423
(Interval Too Brief) during a SIP REGISTER request?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>I want to prevent clients to (re)register with a low
expire-time and thus spam our network.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>The “sip-force-expires”-variable would
work but don’t seem to be SIP-compliant to me.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>From RFC 3261:<o:p></o:p></span></font></p>
<pre><font size=2 face=Arial><span lang=EN-GB style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></pre><pre><font size=2
face=Arial><span lang=EN-GB style='font-size:10.0pt;font-family:Arial'> </span></font>10.3 Processing REGISTER Requests<font
color=black><span style='color:black'><o:p></o:p></span></font></pre>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-GB
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<pre><font size=2 face="Courier New"><span lang=EN-GB style='font-size:10.0pt'> <font
color=black><span style='color:black'>When receiving a REGISTER request, a registrar follows these steps:<o:p></o:p></span></font></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;color:black'> <o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;color:black'> (...)<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;color:black'><o:p> </o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt;color:black'> </span></font><font
color=black><span lang=EN-GB style='color:black'>7. The registrar now processes each contact address in the Contact<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> header field in turn. For each address, it determines the<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> expiration interval as follows:<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> - If the field value has an "expires" parameter, that value<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> MUST be taken as the requested expiration.<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> - If there is no such parameter, but the request has an<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> Expires header field, that value MUST be taken as the<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> requested expiration.<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> - If there is neither, a locally-configured default value MUST<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> be taken as the requested expiration.<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> The registrar MAY choose an expiration less than the requested<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> expiration interval. If and only if the requested expiration<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> interval is greater than zero AND smaller than one hour AND<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> less than a registrar-configured minimum, the registrar MAY<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> reject the registration with a response of 423 (Interval Too<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> Brief). This response MUST contain a Min-Expires header field<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> that states the minimum expiration interval the registrar is<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'> willing to honor. It then skips the remaining steps.<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'><o:p> </o:p></span></font></pre><pre><font size=2
color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'>Thanks in Advance,<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span lang=EN-GB style='font-size:10.0pt;
color:black'>Adam<o:p></o:p></span></font></pre>
<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-GB
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
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