DEFINE_DOWNSTREAM

DEFINE_DOWNSTREAM_LU defines a new downstream LU, and maps it to an upstream host LU or LU pool (defined using DEFINE_LU_0_TO_3 or DEFINE_LU_POOL). This allows the downstream LU to access the host computer using the PU concentration feature of SNAplus2. This verb cannot be used to modify an existing downstream LU.

If you need to activate a downstream LU that is already defined (for example, because the downstream workstation has just been activated), issue the DEFINE_DOWNSTREAM_LU verb for that LU.

VCB Structure

typedef struct define_downstream_lu
{
    AP_UINT16           opcode;                 /* verb operation code       */
    unsigned char            reserv2;           /* reserved                  */
    unsigned char            format;            /* reserved                  */
    AP_UINT16           primary_rc;             /* primary return code       */
    AP_UINT32            secondary_rc;          /* secondary return code     */
    unsigned char            dslu_name[8];      /* Downstream LU name        */
    DOWNSTREAM_LU_DEF_DATA   def_data;          /* Defined data              */
} DEFINE_DOWNSTREAM_LU;

typedef struct downstream_lu_def_data
    unsigned char            description[32];   /* resource description      */
    unsigned char            reserv1[16];       /* reserved                  */
    unsigned char            nau_address;       /* downstream LU nau address */
    unsigned char            dspu_name[8];      /* Downstream PU name        */
    unsigned char            host_lu_name[8];   /* Host LU or Pool name      */
    unsigned char            allow_timeout;     /* Allow timeout of host LU? */
    unsigned char            delayed_logon;     /* Allow delayed logon to    */
                                                /*  host LU                  */
    unsigned char            reserv2[6];        /* reserved                  */
} DOWNSTREAM_LU_DEF_DATA;

Supplied Parameters

The application supplies the following parameters:

opcode

AP_DEFINE_DOWNSTREAM_LU

dslu_name

Name of the downstream LU that is being defined. This is an 8-byte type-A EBCDIC string (starting with a letter), padded on the right with EBCDIC spaces.

def_data.description

A null-terminated text string (0-31 characters followed by a null character) describing the downstream LU. This string is for information only; it is stored in the node's configuration file and returned on the QUERY_DOWNSTREAM_LU verb, but SNAplus2 does not make any other use of it.

def_data.nau_address

Network accessible unit address of the downstream LU. This must be in the range 1-255.

def_data.dspu_name

Name of the downstream PU associated with this LU (as specified on the DEFINE_LS). This is an 8-byte type-A EBCDIC string (starting with a letter), padded on the right with EBCDIC spaces.

def_data.host_lu_name

Name of the host LU or host LU pool that the downstream LU will be mapped onto. This is an 8-byte EBCDIC string, padded on the right with EBCDIC spaces.

For PU concentration, the host LU cannot be a dependent LU type 6.2. However, if the downstream LU is LU type 6.2, you can configure the host LU as an LU type 0-3 and specify that the model type for the host LU is unknown.

def_data.allow_timeout

Specifies whether to allow the session between the downstream LU and the upstream LU to timeout if the session is left inactive for the timeout period specified on the upstream LU definition. Possible values are:

AP_YES: Allow the session this downstream LU has with the upstream LU to timeout.
AP_NO: Do not allow the session this downstream LU has with the upstream LU to timeout.

def_data.delayed_logon

Specifies whether to use delayed logon with this downstream LU (the upstream LU is not activated until the user requests it). Possible values are:

AP_YES: Use delayed logon with this downstream LU; the upstream LU is not activated until the user requests it.
AP_NO: Do not use delayed logon with this downstream LU.

Returned Parameters: Successful Execution

If the verb executes successfully, SNAplus2 returns the following parameters:

primary_rc: AP_OK

Returned Parameters: Parameter Check

If the verb does not execute because of a parameter error, SNAplus2 returns the following parameters:

primary_rc

AP_PARAMETER_CHECK

secondary_rc

Possible values are:

AP_INVALID_DNST_LU_NAME: The supplied dslu_name parameter contained a character that was not valid.
AP_INVALID_NAU_ADDRESS: The supplied NAU address was not in the valid range.
AP_INVALID_ALLOW_TIMEOUT: The supplied allow_timeout parameter value was not valid.
AP_INVALID_DELAYED_LOGON: The supplied delayed_logon parameter value was not valid.

Appendix A “Common Return Codes” lists further secondary return codes associated with AP_PARAMETER_CHECK, which are common to all NOF verbs.

Returned Parameters: State Check

If the verb does not execute because of a state error, SNAplus2 returns the following parameters.

primary_rc

AP_STATE_CHECK

secondary_rc

Possible values are:

AP_INVALID_PU_NAME: The specified dspu_name parameter was not valid.
AP_PU_NOT_DEFINED: The specified dspu_name parameter did not match any defined PU name.
AP_INVALID_PU_TYPE: The PU specified by the dspu_name parameter is not a downstream PU that supports PU concentration.
AP_LU_ALREADY_DEFINED: An LU with the specified name has already been defined, and cannot be modified using this verb.
AP_LU_NAU_ADDR_ALREADY_DEFD: An LU with the specified NAU address has already been defined.
AP_INVALID_HOST_LU_NAME: The specified host LU name was not valid.
AP_LU_NAME_POOL_NAME_CLASH: The specified LU name clashes with the name of an existing LU pool.
AP_PU_NOT_ACTIVE: The PU specified by the dspu_name parameter is not currently active.
AP_LU_ALREADY_ACTIVATING: An LU with the name specified by the dslu_name parameter is currently activating.
AP_LU_DEACTIVATING: An LU with the name specified by the dslu_name parameter is currently deactivating.
AP_LU_ALREADY_ACTIVE: An LU with the name specified by the dslu_name parameter is already active.

Appendix A “Common Return Codes” lists further secondary return codes associated with AP_STATE_CHECK, which are common to all NOF verbs.

Returned Parameters: Function Not Supported

If the verb does not execute successfully because the local node's configuration does not support it, SNAplus2 returns the following parameters:

primary_rc

AP_FUNCTION_NOT_SUPPORTED: The local node does not support PU concentration; this is defined by the pu_conc_supported parameter on the DEFINE_NODE verb.

Returned Parameters: Other Conditions

Appendix A “Common Return Codes” lists further combinations of primary and secondary return codes that are common to all NOF verbs.

DEFINE_DOWNSTREAM_LU

Technical documentation

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VCB Structure

Supplied Parameters

Returned Parameters: Successful Execution

Returned Parameters: Parameter Check

Returned Parameters: State Check

Returned Parameters: Function Not Supported

Returned Parameters: Other Conditions