Parameter Description for TPDEF

AUTOINTV=nnn|32
Specifies the autologon timer interval (10-600 seconds) (the time between JES2 automatic logon attempts) for this installation. The timer is necessary only when a previous logon attempt by an autologon remote has failed or messages are queued for the remote, and the normal events (output for the remote, JES2 RJE resources becoming available, and so forth) that would drive the autologon scan have not occurred.

Proper specification of this parameter decreases the number of unnecessary output searches. Too low a number could cause excessive time spent searching the queues, resulting in performance degradation. Too high a number could cause excessive spool usage because messages for remotes that are not logged on are using up the spool.

Modification: $T TPDEF operator command.

BSCBUF=
Specifies information about the BSC teleprocessing buffers JES2 allocates below 16 megabytes in virtual storage.
LIMIT=nnnn
Specifies the maximum number (10-9999) of BSC teleprocessing buffers JES2 allocates below 16 megabytes in virtual storage.

Performance Considerations: Each signed-on JES2 multileaving terminal requires at least two JES2 teleprocessing buffers. Each signed-on NJE member requires at least two JES2 teleprocessing buffers and should normally have one additional for input, one additional for each output transmitter, plus additional (spare) buffers for console and path manager communications. All other signed-on terminals require at least one buffer each.

If a multileaving terminal has more than one output function running concurrently, additional buffers can be used to increase performance. If your installation is not storage-constrained and can tolerate a greater use of virtual storage, over specifying the LIMIT= parameter on the BUFDEF statement and the LIMIT= parameter on this statement can prove useful. Over specifying these parameters can prevent system degradation caused by a lack of available buffers and does not increase the working set for buffers which are not used. For additional information, see the SIZE= subparameter and the MBUFSIZE= parameter.

This parameter defaults to the greater of either: 
2 x (number of BSC lines specified by LINE(nnnnn) statements)
                         --or--
10

Modification: $T TPDEF operator command to increase the limit. Hot Start to decrease the limit.

SIZE=nnnn|520
Specifies the size (520-3960) in bytes of the BSC teleprocessing buffers JES2 allocates below 16 megabytes in virtual storage.
Note: Use the $D NJEDEF command to display the actual SIZE= value.

If necessary, JES2 increases the value specified for SIZE= without notice to the appropriate minimum value indicated above if RMT(nnnnn) initialization statements are specified for the above terminal types with the indicated features.

Performance Considerations: BSC buffers do not span MVS™ pages. Therefore, be certain that the value specified for this parameter allows for reasonable utilization of a 4K-page after JES2:
  • Adds the 24-byte buffer prefix plus the 112-byte IOB (input/output buffer) for a total of 136 bytes.
  • Does any necessary automatic upward rounding to a multiple of 8, and to evenly fit buffers on a page.

Modification: Warm start.

WARN=nnn|80
Specifies a threshold percentage (0-100) of the maximum use of teleprocessing buffers below 16 megabytes in virtual storage at which JES2 issues the $HASP050 to warn the operator of a resource shortage. If you specify 0, no alert is given.

Modification: $T TPDEF operator command.

SNABUF=
Specifies information about the SNA teleprocessing buffers JES2 allocates above 16 megabytes in virtual storage.
Note: If necessary, JES2 increases the value specified for SIZE= without notice if the BUFSIZE= parameter on the RMT(xx) statement is larger than the specified size on the TPDEF statement. Also note that any change to buffer size will affect both RJE and NJE.
LIMIT=nnnn
Specifies the maximum number (10-9999) of teleprocessing buffers JES2 allocates above 16 megabytes in virtual storage.
LIMIT= defaults to the greater of either: 
2 x (number of SNA lines specified by LINE(nnnnn) statements)
                         --or--
10

Modification: $T TPDEF operator command to increase the limit. Hot Start to decrease the limit.

SIZE=nnnn|400
Specifies the size (256-32512) in bytes of the JES2 teleprocessing buffers JES2 allocates above 16 megabytes in virtual storage.
Performance Considerations: Be certain that the value specified for this parameter allows for reasonable utilization of a 4K-page after JES2:
  • Adds the 24-byte buffer prefix plus the 232-byte RPL (request parameter list) for a total of 256 bytes.
  • Does any necessary automatic upward rounding to a multiple of 8, and to evenly fit buffers on a page.

Modification: Warm start.

WARN=nnn|80
Specifies a threshold percentage (0-100) of the maximum use of teleprocessing buffers above 16 megabytes in virtual storage at which JES2 issues the $HASP050 to warn the operator of a resource shortage. If you specify 0, no alert is given.

Modification: $T TPDEF operator command.

MBUFSIZE=nnnn|400
Specifies the size (128-3960) in bytes (dependent upon JES2 macro expansions) of each JES2 multileaving buffer. The specification for this parameter must be a positive even integer. Satisfactory support of one device of each type (reader, printer, punch console) on 8K-terminal processors is based on the assumption that MBUFSIZE= not be increased above 400, even if support of a non-programmable terminal requires increasing the value specified in the BSCBUF= parameter to 516. In support of 8K-multileaving workstations, this parameter can be increased above 400 if the BUFSIZE= parameter on the corresponding RMT(nnnnn) statement is likewise increased. A smaller multileaving buffer size may be specified for a particular remote terminal on its RMT(nnnnn) initialization statement.
MBUFSIZE= must be a multiple of 2. If not, it is automatically rounded up. If the value specified is greater than that specified on SIZE= for BSCBUF= on SNABUF=, then BSCBUF= and SNABUF= are rounded up.
Note:
  1. To avoid having the SIZE= subparameters for both BSCBUF= and SNABUF= overwritten by the MBUFSIZE= parameter, ensure that the value of both SIZE= subparameters is greater than that specified by MBUFSIZE=.
  2. This parameter is only valid for BSC-programmable terminals that have been specified as MULTILV=YES and do not also have BUFSIZE= specified. This parameter does not affect hardware remotes, SNA remotes, BSC NJE terminals, or SNA NJE terminals.
  3. If you want a specific multileaving terminal to use a different buffer size, you should explicitly specify that buffer size on the BUFSIZE parameter of the RMT(nnnnn) (BSC) initialization statement.

Modification: Hot start.

RMTMSG=nnn|100
Specifies the maximum number (1-255) of messages that may be queued by RTAM to a multileaving remote console. When the count is exceeded, messages will be spooled until the message backlog for that remote console goes to zero.

Modification: $T TPDEF operator command.

Performance Considerations: Always set the value for RMTMSG= to a value considerably lower than the value set for the BUFNUM= parameter on the CONDEF statement. This will ensure that no one BSC multi console can acquire all of the communication buffers (CMBs) and thereby lock out host console messages.

RMTNUM=nnnnn
Specifies the highest number (0-32767) that can be defined for an RJE workstation on this member. When JES2 is active, RJE workstations cannot be added if they specify a higher subscript than this value.

If you do not specify this parameter or an RMTnnnnn initialization statement specifies an RJE workstation higher than the RMTNUM= specification, JES2 sets RMTNUM= to the highest number specified for an RJE workstation on this member during initialization.

Performance Considerations: Because RMTNUM= allocates storage (68 bytes of storage below 16Mb of virtual storage for each RJE workstations) whether they are defined or not, you should set this parameter low enough to minimize the unused virtual storage at your installation. However, setting this value conservatively higher than the number of currently defined RJE workstations can be useful should you need to add RJE workstations without restarting JES2. See z/OS JES2 Initialization and Tuning Guide for further information on providing for future growth of your RJE workstation environment.

Modification: Hot start.

SESSIONS=
Specifies information about the maximum of VTAM® sessions.
LIMIT=nnnn
Specifies the maximum number (1-9999) of VTAM sessions (nnnnn) that can be active at any one time. Terminals or SNA NJE nodes attempting to log on when nnnnn sessions are already active are not allowed to log on.
If you do not specify a value for this parameter, it defaults to the number of LINE(nnnnn) initialization statements specifying the UNIT=SNA keyword.
Note:
  1. The default value is not sufficient to allow all SNA RJE and NJE lines to be simultaneously connected to JES2 if some of the terminals represent multiple logical units.
  2. Although the valid range for this parameter is 1-9999, if you do not define any sessions, by using the LINE initialization statement with UNIT=SNA defined, SESSIONS= defaults to 0.
Note: Use this parameter to increase the limit for the JNUM resource that is reported on the HASP050 message.
WARN=nnn|80
Specifies a threshold percentage (0-100) of the maximum used number of VTAM sessions at which JES2 issues the $HASP050 to warn the operator of a resource shortage.

Modification: $T TPDEF command.