PK73352: FALL BACK FROM TCP TO UDP IN CASE OF TCP FAILOVER.

Fixes are available

APAR status

Closed as program error.

Error description

A message should be sent over UDP, but because of the message
size constraints SIP container is trying to send it over TCP.
However, it results in a TCP reset. According to the standard in
this case the container "should retry the request, using UDP."

Local fix

```
N/A
```

Problem summary

****************************************************************
* USERS AFFECTED:  Session Initiation Protocol (SIP)           *
*                  users of WebSphere Application Server       *
*                  versions 6.1 and 7.0.                       *
*                  In 6.1, both standalone and cluster         *
*                  deployments.                                *
*                  In 7.0, only standalone deployments.        *
****************************************************************
* PROBLEM DESCRIPTION: When sending out a SIP (Session         *
*                      Initiation Protocol) request over UDP,  *
*                      and the message size exceeds the        *
*                      "Maximum Transmission Unit" (MTU) the   *
*                      container attempts to switch the        *
*                      transport to TCP. If TCP fails, the     *
*                      container needs to fall back to UDP.    *
*                      Falling back to UDP does not work.      *
****************************************************************
* RECOMMENDATION:                                              *
****************************************************************
The problem was caused by missing function in the SIP (Session
Initiation Protocol) container. This function should determine
the TCP failure, and handle it by switching back to UDP.

Problem conclusion

The problem is fixed in the SIP (Session Initiation Protocol)
container. With the fix, the container determines a TCP
failure when it occurs, and takes care of falling back to UDP.

The fix for this APAR is currently targeted for inclusion in
fixpack 7.0.0.5.  Please refer to the Recommended
Updates page for delivery information:
http://www.ibm.com/support/docview.wss?rs=180&uid=swg27004980

The fix is available only on V7.0. Version 6.1 users can work
around the problem, as suggested in the "Circumvention".

Temporary fix

Comments

APAR Information

APAR number
PK73352
Reported component name
WEBSPHERE APP S
Reported component ID
5724J0800
Reported release
61A
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-10-07
Closed date
2009-01-22
Last modified date
2009-01-22

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
WEBSPHERE APP S
Fixed component ID
5724J0800

Applicable component levels

R61A PSY
UP
R61H PSY
UP
R61I PSY
UP
R61P PSY
UP
R61S PSY
UP
R61W PSY
UP
R61Z PSY
UP
R700 PSY
UP

[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"6.1","Line of Business":{"code":"LOB45","label":"Automation"}}]

Document Information

Modified date:
23 October 2021

Tips

PK73352: FALL BACK FROM TCP TO UDP IN CASE OF TCP FAILOVER.

Fixes are available

Subscribe

APAR status

Closed as program error.

Error description

Local fix

Problem summary

Problem conclusion

Temporary fix

Comments

APAR Information

APAR number

Reported component name

Reported component ID

Reported release

Status

PE

HIPER

Special Attention

Submitted date

Closed date

Last modified date

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

Fixed component ID

Applicable component levels

R61A PSY

R61H PSY

R61I PSY

R61P PSY

R61S PSY

R61W PSY

R61Z PSY

R700 PSY

Document Information

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