<html>
<head>
<base href="https://wiki.asterisk.org/wiki">
<link rel="stylesheet" href="/wiki/s/en/2172/18/9/_/styles/combined.css?spaceKey=AST&forWysiwyg=true" type="text/css">
</head>
<body style="background: white;" bgcolor="white" class="email-body">
<div id="pageContent">
<div id="notificationFormat">
<div class="wiki-content">
<div class="email">
<h2><a href="https://wiki.asterisk.org/wiki/pages/viewpage.action?pageId=20185363">Who Hung Up?</a></h2>
<h4>Page <b>added</b> by <a href="https://wiki.asterisk.org/wiki/display/~kmoore">Kinsey Moore</a>
</h4>
<br/>
<div class="notificationGreySide">
<h1><a name="WhoHungUp%3F-Overview"></a>Overview</h1>
<p>Usage of SIP_CAUSE has been known for a while now to impact performance in some situations due to the use of the MASTER_CHANNEL dialplan function which must scan through the channel list. Another issue with SIP_CAUSE is that it is too technology-specific. The HANGUPCAUSE hash resolves these issues by passing this data via control frames and creating a more generic mechanism that all channel technologies can share. This allows the channel and cause code information to move through Asterisk's core along with other control frames to the parent channel.</p>
<h1><a name="WhoHungUp%3F-DifferencesinUsage"></a>Differences in Usage</h1>
<p>HANGUPCAUSE may be used in any situation that calls for SIP_CAUSE as a drop-in replacement if only SIP channels are being called. If used with non-SIP channels, dialplan code using HANGUPCAUSE must be able to handle non-SIP cause codes or be able to safely ignore them. SIP_CAUSE has also been modified to use HANGUPCAUSE as its backend to take advantage of better performing code.</p>
<h1><a name="WhoHungUp%3F-Example"></a>Example</h1>
<div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent">
<pre class="theme: Confluence; brush: java; gutter: false">[foo]
exten => s,1,Dial(SIP/bar)
exten => h,1,noop()
exten => h,n,set(HANGUPCAUSE_STRING=${HASHKEYS(HANGUPCAUSE)})
; start loop
exten => h,n(hu_begin),noop()
; check exit condition (no more array to check)
exten => h,n,gotoif($[${LEN(${HANGUPCAUSE_STRING})} = 0]?hu_exit)
; pull the next item
exten => h,n,set(ARRAY(item)=${HANGUPCAUSE_STRING})
exten => h,n,set(HANGUPCAUSE_STRING=${HANGUPCAUSE_STRING:${LEN(${item})}})
; display the channel ID and cause code
exten => h,n,noop(got channel ID ${item} with pvt cause ${HASH(HANGUPCAUSE,${item})})
; check exit condition (no more array to check)
exten => h,n,gotoif($[${LEN(${HANGUPCAUSE_STRING})} = 0]?hu_exit)
; we still have entries to process, so strip the leading comma
exten => h,n,set(HANGUPCAUSE_STRING=${HANGUPCAUSE_STRING:1})
; go back to the beginning of the loop
exten => h,n,goto(hu_begin)
exten => h,n(hu_exit),noop(All HANGUPCAUSE entries processed)</pre>
</div></div>
<h1><a name="WhoHungUp%3F-SupportforOtherChannelDrivers"></a>Support for Other Channel Drivers</h1>
<p>The implementation that HANGUPCAUSE and the modified SIP_CAUSE use is extensible to other channel technologies as well. Work to support these other channel technologies is in progress.</p>
<h1><a name="WhoHungUp%3F-UnderstandingtheInformationProvided"></a>Understanding the Information Provided</h1>
<p>In an effort to allow consumers of this information to better understand what is available, translation facilities will be provided that allow conversion of cause codes from one channel technology to another. This work is also in progress.</p>
</div>
<div id="commentsSection" class="wiki-content pageSection">
<div style="float: right;" class="grey">
<a href="https://wiki.asterisk.org/wiki/users/removespacenotification.action?spaceKey=AST">Stop watching space</a>
<span style="padding: 0px 5px;">|</span>
<a href="https://wiki.asterisk.org/wiki/users/editmyemailsettings.action">Change email notification preferences</a>
</div>
<a href="https://wiki.asterisk.org/wiki/pages/viewpage.action?pageId=20185363">View Online</a>
|
<a href="https://wiki.asterisk.org/wiki/pages/viewpage.action?pageId=20185363&showComments=true&showCommentArea=true#addcomment">Add Comment</a>
</div>
</div>
</div>
</div>
</div>
</body>
</html>