FCTC Line Driver Compatibility

The 6.3 FCTC line driver is incompatible with previous releases of FCTC. To address this incompatibility in version 6.3 SP1, an Entire Net-Work CTC Option L001 library was made available to you that enabled compatible FCTC connections between 6.3 and 6.2 SP2 nodes. This L001 library provided code that allowed a 6.3 node to detect a connection to a prior version of FCTC and automatically convert that connection to a compatible 6.2 SP2 connection.

This FCTC compatibility processing has been automatically included in Entire Net-Work CTC Option 6.3 SP2. You no longer need the L001 library. Activation of compatibility mode is controlled using an FCTC DRIVER parameter called COMPAT. For complete information about the COMPAT parameter, read CTCA and FCTC DRIVER Statements.

No changes to your 6.2 SP2 nodes are required. However, if FCTC line driver compatibility has been activated, Entire Net-Work must not be started with REUSASID=YES.

This document covers the following topics:


Activating FCTC Line Driver Compatibility Processing

By default, FCTC line driver compatibility processing is already activated when you install version 6.3 SP2 or later. However, you can follow these steps to verify that activation is in place.

Start of instruction setTo activate FCTC line driver compatibility processing, complete the following steps:

  1. Edit your FCTC line driver DRIVER statement and verify it includes the COMPAT parameter set to "Y". (To deactivate FCTC line driver compatibility processing, you would set the COMPAT parameter to "N".) For more information, read CTCA and FCTC DRIVER Statements.

  2. Start Entire Net-Work 6.3.

    Note:
    If FCTC line driver compatibility has been activated, Entire Net-Work must not be started with REUSASID=YES.

    The FCTC line driver compatibility code is activated and ready to be used.

    Note:
    No changes are necessary to your existing Entire Net-Work version 6.2 SP2 nodes.

How It Works

This section describes the internal process used by the Entire Net-Work CTC Option to handle FCTC connections once compatibility is activated and a 6.3 FCTC line driver is defined.

When an Entire Net-Work version 6.3 node initializes, both the 6.3 FCTC line driver and a version 6.2 SP2 FCTO line driver are initialized. The FCTO line driver uses the same parameters that were specified for the FCTC driver.

Warning:
Do NOT define the FCTO line driver in the Entire Net-Work startup parameters.

When a connection attempt with an Entire Net-Work 6.2 SP2 node (the partner connection) is detected, the connection is automatically converted to the FCTO line driver, as follows:

  1. The version 6.3 link is closed and marked disabled.

  2. If a pair of matching FCTO links is found, these are used for the connection. If no matching FCTO links exist, a pair of FCTO links is created. The parameters for these links are determined from the parameters used for the version 6.3 link; so no formal FCTO line driver definition should be attempted.

    The name of the new link is based on the length of the version 6.3 link name and checks for duplicate link names. If the 6.3 link name is less than eight characters long, an "R" is appended to the link name to create the FCTO read link name and a "W" is appended to create the FCTO write link name. If the 6.3 link name is eight characters long, the eighth character is replaced by "R" or "W" to create the read and write FCTO link names. If the newly created FCTO links have names that are duplicated by others in the system, then the link name is generated in the format FCTOxnnn, where x is "R" or "W" (to identify the read or write link), and nnn is a unique positive integer.

  3. The connection is established using the pair of FCTO links.

When the partner node is upgraded to Entire Net-Work 6.3, the connection is automatically converted back to a version 6.3 connection as follows:

  1. The pair of FCTO links are closed and marked disabled.

  2. The original version 6.3 FCTC link is located and reopened.

  3. The connection is established using the original 6.3 FCTC link. You do not need to restart the existing 6.3 node after upgrading the partner node; the connection happens automatically.

Important Usage Notes

The following important usage notes should be remembered:

  1. Do not define the FCTO line driver in your Entire Net-Work parameters, the way you would for other line drivers. The FCTO line driver parameters are initialized automatically as they are needed when FCTC compatibility is activated.

  2. Do not make any changes to your existing Entire Net-Work 6.2 SP2 nodes to implement compatibility with version 6.3 nodes.

  3. Operator commands can be issued to the FCTO line driver and links. However, do not use operator commands to attempt to convert between the two types of connections; this is handled automatically.

  4. You do not need to restart the version 6.3 node once the connection partner has also upgraded to 6.3. The connection will automatically be converted back to a 6.3 connection.

  5. You cannot use the FCTO line driver to establish connections between two version 6.3 nodes.

  6. If FCTC line driver compatibility is not activated, and an FCTC connection to a version 6.2 SP2 node is attempted, the connection will fail with error NETC121E.

  7. If FCTC line driver compatibility has been activated, Entire Net-Work must not be started with REUSASID=YES.