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PK79656: RFC 3263 SKIPPING NAPTR AND SRV LOOKUP WHEN LOCATING A SERVER

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You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • When the application attempts to send out a SIP (Session
    Initiation Protocol) request, and the container is configured to
     locate servers using DNS, it skips SRV and NAPTR lookups.
    This causes the message to be delivered to the wrong address.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED:  Session Initiation Protocol (SIP) users of  *
    *                  WebSphere Application Server V6.1           *
    ****************************************************************
    * PROBLEM DESCRIPTION: The SIP (Session Initiation Protocol)   *
    *                      container does not perform necessary    *
    *                      DNS queries for locating a server.      *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    The problem occurs when the SIP container is configured to
    follow RFC 3263 for sending out a request. This is disabled by
    default, and enabled by setting the custom property
    SIP_RFC3263_nameserver.
    According to RFC 3263, if the request URI contains no
    transport parameter, the transport is resolved by querying DNS
    for the NAPTR record of the domain. If the request URI
    contains no port number, the port is resolved by querying DNS
    for the SRV record of the domain.
    For example, if the request URI is sip:example.com then it is
    necessary to query DNS for both NAPTR and SRV.
    The problem is that the container puts the default port number
    and the default transport parameter in the request URI before
    processing RFC 3263 flow. For example, it changes
    sip:example.com to sip:example.com:5060;transport=udp. Later
    on, when RFC 3263 processing takes place, the URI already
    contains a port number and a transport parameter, causing the
    necessary DNS query, for NAPTR and SRV, to be skipped.
    Typically, this results in the request being sent to the wrong
    destination, or through the wrong transport.
    

Problem conclusion

  • The problem is fixed in the SIP (Session Initiation Protocol)
    container. The code no longer skips the necessary NAPTR/SRV
    DNS queries.
    
    The fix for this APAR is currently targeted for inclusion in
    fixpack 6.1.0.23.  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 number

    PK79656

  • Reported component name

    WEBSPHERE APP S

  • Reported component ID

    5724J0800

  • Reported release

    61I

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2009-01-29

  • Closed date

    2009-02-04

  • Last modified date

    2009-02-04

  • 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

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Document Information

Modified date:
04 February 2009