PH53665: SIPCONTAINER FORWARDS RETRANSMITTED ACK WHEN ALLOW.LOWER.CSEQ.IN.ACK IS SET TO TRUE

APAR status

• Closed as program error.

Error description

• Sipcontainer forwards retransmitted ACK when
  allow.lower.cseq.in.ack is set to true
  

Local fix

• NA
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:  All users of IBM WebSphere Application      *
  *                  Server                                      *
  *                  who are using SIP and are setting the       *
  *                  sipcontainer custom property                *
  *                  allow.lower.cseq.in.ack to true.            *
  ****************************************************************
  * PROBLEM DESCRIPTION: Sipcontainer will accept ACK with the   *
  *                      wrong CSeq number. SIP dialog will      *
  *                      progress in case of retransmitted ACK.  *
  ****************************************************************
  * RECOMMENDATION:  Delete custom property                      *
  *                  allow.lower.cseq.in.ack                     *
  *                  or set it to false. Alternatively, once     *
  *                  these                                       *
  *                  changes are delivered, one can set          *
  *                  sipcontainer custom property                *
  *                  compare.ack.cseq.to.2xx.response to true.   *
  ****************************************************************
  If the custom property allow.lower.cseq.in.ack is set to true
  the
  sipcontainer does not valide the CSeq number of ACK requests.
  This
  results in the dialog progressing in case any ACK arrives to the
  sipcontainer, including retransmissions of previously handled
  ACK
  requests caused by network latency. This can result in call
  failures on the client side.
  

Problem conclusion

• The fix for this APAR is targeted for inclusion in fix packs
  8.5.5.25 and 9.0.5.17. For more information, see 'Recommended
  Updates for WebSphere Application Server':
  https://www.ibm.com/support/pages/node/715553
  

Temporary fix

• Delete custom property allow.lower.cseq.in.ack or set it to fals
  

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

  WEBS APP SERV N

• Fixed component ID

  5724H8800

Applicable component levels