FIX: Rapid Transport Protocol (RTP) connections may not be reset correctly when IP-DLC connections are restarted on Host Integration Server 2004 systems

Rapid Transport Protocol (RTP) connections may not be reset correctly when IP-DLC connections are restarted on Microsoft Host Integration Server 2004 systems.

This problem occurs because an IP-DLC connection may reconnect to an IBM mainframe by using the same Transport Connection Identifier (TCID) value that a previous IP-DLC connection used. The IP-DLC link service is designed to increment the TCID value from a starting value of 0. This behavior may result in duplicate TCID values being included in the RTP header for different IP-DLC connections.

These duplicate TCID values may also make it difficult to distinguish RTP packets in network traces when you are examining multiple IP-DLC connections.

Hotfix information

A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

File information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.Note Because of file dependencies, the most recent hotfix that contains these files may also contain additional files.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

After you apply the hotfix, the IP-DLC link service randomly generates the TCID value. This behavior prevents duplicate TCID values in RTP connections.

For more information about Advanced Peer-to-Peer Networking (APPN), about High Performance Routing (HPR), and about RTP connections in APPN/HPR networks, visit the following IBM Web site:Note RTP connections and the TCID parameter of the RTP Transport Header are discussed in Chapter 8 of Inside APPN and HPR - The Essential Guide to New SNA.

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