User damian glenny - Mr Watson, Come Heremost recent 30 from http://mrwatsoncomehere.com2010-07-30T02:27:37Zhttp://mrwatsoncomehere.com/feeds/user/3http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mrwatsoncomehere.com/questions/2/what-does-the-name-of-this-site-mean-who-was-mr-watson/5#5Answer by Damian Glenny for What does the name of this site mean? Who was Mr Watson?Damian Glenny2009-10-12T09:56:20Z2009-10-13T05:51:35Z<p>"Mr Watson, come here - I need you" was the first sentence successfully transmitted using a telephone; it was spoken by Alexander Graham Bell in 1876 to his assistant Thomas A. Watson. Isn't Wikipedia wonderful?</p>
<p>It seemed appropriate that a telecommunications site should pay homage to one of the landmark moments of the field, and doubly appropriate that a - slightly manufactured - plea for help should become the theme.</p>
http://mrwatsoncomehere.com/questions/7/what-does-a-connfail-correlate-toWhat does a CONNFAIL correlate to?Damian Glenny2009-10-12T21:56:09Z2009-10-12T21:56:09Z
<p>Looking specifically at an IS-826 deployment using ANSI TCAP, what should a CONNFAIL use as the invoke correlation?</p>
<p>I believe that the message flow in a compliant environment will look like this, somewhat abstracted:</p>
<ul>
<li>ANLYZD tid anlyzd-tid cid anlyzd-cid</li>
<li>CONNRES tid connres-tid-anlzyd-tid cid connres-cid-anlyzd-cid</li>
<li>CCDIR tid ccdir-tid cid ccidr-cid</li>
<li>ccdir_rr tid ccdir-tid cid ccdir-cid (try saying that three times fast)</li>
<li>RESETTIMER tid connres-tid-anlzyd-tid cid connres-cid+1-anlyzd-cid</li>
<li>...</li>
<li>CONNFAIL tid anlyzd-tid-connres-tid cid anlyzd-cid+1-last-reset-timer-cid</li>
<li>anlyzd_rr tid anlyzd-tid cid anlyzd-cid</li>
</ul>
<p>I think that this implies a CONNRES dialogue needs to remain available until either:</p>
<ul>
<li>a CONNFAIL is received on it</li>
<li>a DISCONNRES is sent on it</li>
<li>(optionally) CCDIR failure tears the call down</li>
</ul>
<p>This doesn't dovetail very well with the optionality of CCDIRs - how do you avoid potential call leaks without timers on an invoking dialogue? Do you rely on the MSC having a timer fire off the ANLYZD? Wouldn't the CONNRES force that to be elided?</p>