PM29534: DIALOG USGAES ARE NOT ADDED OR REMOVED CORRECTLY AS SPECIFIED BY RFC 5057

APAR status

• Closed as program error.

Error description

• Several methods in Session Initiation Protocol (SIP) can
  establish a dialog. When they do so, they also establish an
  association between the endpoints within that dialog.  This
  association has been known for some time as a "dialog usage"
  in the developer community.  A dialog initiated with an INVITE
  request has an invite usage. A dialog initiated with a
  SUBSCRIBE request has a subscribe usage.  A dialog initiated
  with a REFER request has a subscribe usage. Dialogs with
  multiple usages arise when a usage-creating action occurs
  inside an existing dialog.  Such actions include accepting a
  REFER or SUBSCRIBE issued inside a dialog established with an
  INVITE request.
  
  The problem is that the current implementation of this feature
  is not working correctly and dialog usages are not
  added/removed correctly. For example, a subscribe usage within
  an existing dialog is not added to the usages table, and a
  terminating response doesn't remove its dialog usage.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:  IBM Websphere Application Server version    *
  *                  7.0 Feature Pack for Communications         *
  *                  Enabled Applications (CEA) Session          *
  *                  Initiation Protocol (SIP) users             *
  ****************************************************************
  * PROBLEM DESCRIPTION: Dialog usages are not added or removed  *
  *                      correctly as specified by Request For   *
  *                      Comments (RFC) 5057.                    *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The session state was not updated when receiving another
  initial request on the same dialog, and when a terminating
  response is received. This caused the dialog usages table to
  not get updated as well.
  The tests were also not good, since they did not check the
  result header of the request.
  

Problem conclusion

• The code was updated in the flow of sending a response
  (onSendingResponse()) to update the session state (and thus
  the dialog usages table). In addition, a mechanism was added
  to remove dialog usages when a terminating response is received.
  Tests were fixed as well.
  
  The fix for this APAR is currently targeted for inclusion in
  Feature Pack for CEA fix pack 1.0.0.11.  Please refer to the
  Recommended Updates page for delivery information:
  http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

• Fixed component name

  CEA FEATUREPACK

• Fixed component ID

  5724J0855

Applicable component levels

• R700 PSY

     UP