[Users] multiple 487 created - sr-users

15 Feb 2006


      For the normal cancel situation.
UA1		OPENSER		UA2
--------INVITE----------------->
<-----------100-----------------
    	    --------------------INVITE---------->
    	    <---------------100-------------------
----------CANCEL---------->
    	    --------------CANCEL------------->
    	   <--------------200------------------
    	  <------------487-------------------
    	   --------------ACK----------------->
<---------487---------------
-------------ACK------------>
But in my case, I found that there are many 487 created from openser
to UA1.  The multiple 487 may cause a call drop in the following call.
 Why does openser create so many 487 for UA1?  How can I prevent it?
UA1		OPENSER		UA2
--------INVITE----------------->
<-----------100-----------------
    	    --------------------INVITE---------->
    	    <---------------100-------------------
----------CANCEL---------->
    	    --------------CANCEL------------->
    	   <--------------200------------------
    	  <------------487-------------------
    	   --------------ACK----------------->
<---------487---------------
-------------ACK------------>
<---------487-------------
-------------ACK------------>
<---------487---------------
-------------ACK------------>
<---------487-------------
-------------ACK------------>
<---------487-------------
-------------ACK------------>
<---------487-------------
-------------ACK------------>
<---------487-------------
-------------ACK------------>
...