Hello,<br>I have a question about what the proper way to handle a duplicate presentation of an INVITE is. On occasion I am seeing some packet loss and/or timing issues which are causing some of my end-points to retransmit the INVITE. Here is what I am doing in the most basic sense:<br>
<br><br>ITSP (Bandwidth.com) --> INVITE --> KAMAILIO --> DISPATCHER --> Asterisk (B2BUA)<br><br><br>I am seeing Bandwidth.com send an INVITE which I already received. I keep track of all running transactions in a htable which has a key of <br>
<br>$ci::$cs::$ft (as per RFC 3261).<br><br>If I get an invite for something which already has a key in the hashmap, I am currently sending a "482 Loop
Detected", but I don't think that is correct as it causes the whole call
to tear down instead of letting it continue and assuring Bandwidth.com that I received the initial INVITE and am currently working on it.<br><br>This is what I am currently doing:<br><br> ##<br> ## Check to make sure we don't already have an active<br>
## transaction for this call-id, c-seq, and from-tag<br> ## RFC3261 - 8.2.2.2<br> ##<br> ## We are going to add a key for this unique record if one<br> ## doesn't already exist. The key automatically times out <br>
## after 30 seconds, so we need not worry about cleanup<br> ##<br> if($sht(loop_check=>$ci::$cs::$ft) == null){<br> xlog("L_INFO","No transaction found, adding to our hashtable\n");<br>
$sht(loop_check=>$ci::$cs::$ft) = 1; <br> }else{<br> xlog("L_ERR","Loop Detected: $ci::$cs::$ft\n");<br> sl_send_reply("482","Loop Detected - Duplicate Session Presentation");<br>
exit;<br> }<br><br>Can I just swallow the second INVITE and do an exit; in my script?<br>Should I do an sl_send_reply(100,"Trying")?<br><br>Any advice would be greatly appreciated.<br><br>Thanks,<br>