Attempts to update a backtranslation softlink entity in the specified
    namespace.  In order words, the node will attempt to ensure that the
    backtranslation softlink information present in its session control
    database is consistent with the softlink information in the
    DECdns namespace.

    update  [node node-id] session control -
             backtranslation softlink softlinkname

    Normally, all the node's backtranslation softlinks are periodically
    updated in the DECdns namespace when the session control attribute
    maintain backward soft links is true.  However, if updates fail, you
    can use the DNS$CONTROL or DECNET_REGISTER tools to confirm that a
    DECdns server is accessible and that the node's object and softlinks
    are properly configured in the namespace.

    Examples:

    update session control backtranslation softlink -
       WINTER:.DNA_BACKTRANSLATION.%X49.%X0018.%XAA00040052A60
       !  Attempts to update the softlink for DECnet address 24.42
       !    in the WINTER namespace.

    update session control backtranslation softlink -
       WINTER:.DNA_BACKTRANSLATION.%XA1725E45
       ! Attempts to update the softlink for IP address
       !  161.114.94.69 in the WINTER namespace. (OpenVMS only)