Communication link parameters

BARR/RJE

On the Communication Link tab you can specify the BARR/RJE communication protocol and physical attachment between the host system and remote computer. This topic describes the VTAM and NCP parameters you must specify in the BARR/RJE software for the communication link. These parameters must match those specified in the host VTAM and NCP parameter libraries. Your host programmer can provide the correct values to enter into the BARR/RJE software. VTAM is the mainframe program for the SNA communication protocol. NCP is the program that resides in the mainframe communications controllers.

When you finish configuring the communication links on the Communication Link tab, click NCP and Physical Unit to view sample statements the host programmer needs to enter in the host VTAM and NCP parameter libraries. The host programmer must set certain host parameters for BARR/RJE to operate. An existing remote definition used for other RJE equipment might not work with BARR/RJE. You will save time and effort getting your system running if you adhere to the recommended host definition. You can print these screens for the host programmer by clicking Print on the NCP or Physical Unit dialog box.

NCP definitions are available for 802.2 LLC2 and SDLC connections. Physical unit (VTAM) definitions are only available for 802.2 LLC2, HPR/IP, and SDLC switched connections.

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SDLC switched line connections

On SDLC switched (dial) lines, host modems automatically answer remote user phone calls as shown in the following graphic. The modems use the public phone system at speeds from 1,200 to 56,000 bps.

SDLC Switched Line Connections

SDLC dial lines use modems to answer remote phone calls.

The BARR/SNA SDLC Link Service configuration utility and the SDLC Connection Configuration dialog box are used to configure the SDLC link service for the BARR/RJE software. The parameters specified are also used by VTAM and NCP on the mainframe. Your host programmer can provide you with the correct parameter values. After you enter the communication link parameters in the software, BARR/RJE produces samples of the statements the host programmer needs to enter in the host VTAM and NCP parameter libraries. You can view and print these statements by clicking NCP and Physical Unit on the Communication Link tab.

NCP definition for an SDLC switched line

The following is the recommended NCP definition for an SDLC switched line. You can access this dialog box by clicking NCP on the Communication Link tab. The parameters that appear in the dialog box vary depending on the settings configured in the BARR/RJE software. The parameters that change are displayed in blue text.

NCP Definition for Switched Line Dialog Box

GROUP macro

The GROUP macro instruction gives common parameter settings for all LINE macros in the group.

group

GROUP DIAL=Yes,LNCTL=SDLC

Required parameters

Parameter

Description

group

Optional macro label.

DIAL=Yes

Indicates this is a dial-up line.

LNCTL=SDLC

Indicates the line control is SDLC.

LINE macro

The LINE macro defines the line at the host and is necessary for SDLC connections.

linename LINE

ADDRESS=(aaa,FULL),DUPLEX=FULL,

X

 

NRZI=Yes,RETRIES=(8,2,20),SPEED=nnnnnn,TRANSFR=16

 

Required parameters

Parameter

Description

linename

The VTAM name of the communications line.

ADDRESS=

Line interface address.

(aaa,FULL) – Indicates the line interface address, aaa, when you specify DATMODE=FULL.

aaa – Indicates the line interface address, aaa, when you specify DATMODE=HALF.

DUPLEX=FULL

The line and modem can send and receive data simultaneously.

NRZI=YES|NO

NRZI is a method to encode binary data over a serial interface. Check if your host uses NRZI encoding.

YES – Use NRZI encoding. Use this option if frequent SDLC aborts occur.

NO – Do not use NRZI encoding.

RETRIES=(m,t,n)

The number of attempts the system will make to recover from communications errors.

m – Maximum retransmissions of a frame while waiting for a normal response. The recommended value is 8.

t – Time in seconds paused after m retransmissions have failed. The recommended value is 2.

n – Number of times the above error recovery sequence is repeated. The recommended value is 20.

SPEED=nnnnnn

Required. Because the modem provides the bits-per-second clock, this parameter does not affect BARR/RJE functions, but the IBM Network Performance Monitor uses this value to calculate statistics.

TRANSFR=16

The number of NCP buffers. This value corresponds to the maximum amount of data (the data transfer limit) that NCP will receive from the line during a single data transfer operation.

System default values

Parameter

Description

CHECK=NODCD

The Data Carrier Detect (DCD) line from the modem will not be monitored.

CLOCKNG=EXT

External clocking indicates that the modem’s clock will control the transmission rate.

PU macro

The PU macro names and describes a PU. At log on, the PU macro in the NCP definition is replaced with the PU macro from VTAM.

puname

PU

MAXLU=5

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

MAXLU=n

The maximum number of LUs used with this line. Use the LU macro formula to calculate the number of LUs you need. If you are upgrading from DOS-based BARR/RJE, the number of Non-RJE LUs specified on the Communication Link tab is also included in the calculation.

Physical Unit definition for SDLC switched line

PU Definition for Switched Line Dialog Box

PU macro

The PU macro names and describes a physical unit.

puname

PU

ADDR=C1,

X

 

 

IDBLK=03D,DATMODE=FULL,

X

 

 

IDNUM=12345,

X

 

 

MAXDATA=1033,MAXOUT=7,

X

 

 

PACING=7,PASSLIM=7,VPACING=7

 

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

ADDR=C1

The 8-bit address used by SDLC. This address, the first byte of every frame, separates messages sent to different PUs on the same line.

DATMODE=FULL|HALF

Specify whether the PU data mode is full duplex or half duplex.

FULL – Default. The system sends and receives data simultaneously resulting in twice the throughput. The V.32 modem standard supports full duplex on dial-up lines. Some modems do not support full-duplex communications.

If you select DATMODE=FULL on the BARR/SNA SDLC Link Service Link tab, the host programmer must also specify it at the host. If the computer and host settings do not match, the software might have communication problems such as timeouts or lowered performance when it sends data to the host.

HALF – In half duplex, the communications line is in either a send or receive mode so less than half the capacity of the line is available for use.

To maximize performance, select DATMODE=FULL on the SDLC Connection Configuration dialog box and in the VTAM PU definition. You can achieve maximum BARR/RJE performance with full-duplex mode. Full duplex enables you to send and receive data simultaneously, often doubling throughput. You can even improve one-way throughput because you can receive acknowledgments while you send data.

IDBLK=bbb
IDNUM=nnnnn

Use these parameters to identify the remote’s PU definition. During Xid negotiation, the remote sends an Exchange ID that contains the IDBLK and IDNUM parameters. VTAM searches for the PU identified by IDBLK and IDNUM and uses this PU for the rest of the communications session.

MAXDATA=265|521|1033|2057

The maximum amount of data you can send on the PU in one frame. This value includes nine bytes of header information plus the data length. The default value is 1033.

To maximize performance, you can increase throughput by sending larger frames of data. Send 1024 bytes by setting MAXDATA to 1033 on the SDLC Connection Configuration dialog box and the VTAM PU definition. This step reduces the amount of control information and total number of frames sent. Setting MAXDATA to 2057 can result in greater system throughput, but it is not recommended for Ethernet or other LAN equipment that will not support the larger packet size.

MAXOUT=7

Specifies that up to 7 frames of information will be sent before pausing for a response. The maximum MAXOUT value of 7 results in the highest throughput.

PACING=n

Determines how much data gets sent to BARR/RJE before the system needs a pacing response to send more data. Pacing is a flow-control mechanism that prevents the host from sending data faster than BARR/RJE can print or otherwise handle it. Values smaller than 7 often lower performance. This parameter overrides the SRCVPAC value in the LOGMODE.

PASSLIM=n

The maximum number of information frames sent to the PU at one time. This parameter is usually set to the same value as MAXOUT.

VPACING=n

Similar to the PACING parameter, but VPACING determines pacing between the RJE system and VTAM. Values less than 7 lower efficiency.

To maximize performance, setting parameters to larger values can improve BARR/RJE performance. If PACING=7 and VPACING=7 in the VTAM PU definition, the host can send seven data frames before it requires a pacing response. On a half-duplex line, the host sends 7 frames at a time. When you specify PACING=7, the pacing response could be returned in time for 7 more frames of data to be sent. Include MAXOUT=7 in the PU definition.

System default values

Parameter

Description

DISCNT=(NO)

Do not disconnect the PU until BARR/RJE requests it.

ISTATUS=ACTIVE

The PU will be activated automatically.

PUTYPE=2

BARR/RJE uses the Physical Unit Type 2 protocol.

Other parameters

Parameter

Description

DLOGMOD=nnnnnnnn

Specify the logon mode table entry to use by default.

MODETAB=nnnnnnnn

Specify the mode table containing the logmode entries. ISTINCLM is the default IBM-supplied mode table usually present with VTAM.

SSCPFM=USSSCS

If this parameter is set, then the host's logon type and the Logon type selected on the RJE Description tab, must be configured as Character Coded. The system default is SSCPFM=FSS, which indicates that the Logon type must be Formatted.

LU macro

The LU macro instructions define logical units allocated to the RJE devices.

luname02 LU

LOCADDR=2,

**  RJE  LU

Use the LU macro formula to calculate the number of LUs you need.

Required parameters

Parameter

Description

lunamenn

The LU name conforms to the naming convention at your site. BARR/RJE does not use this name.

LOCADDR=i

The local addresses must be unique. The maximum value for i is 20 when you use Barr software. MVS/JES2 supports a maximum of 13 LUs with BARR/RJE.

BATCH=YES

Indicates the processing priority. Batch applications, such as RJE, require low priority. While interactive applications, such as 3270 terminal sessions, usually have higher priority.

For VTAM Version 4, Release 3 or later, replace this parameter with the Class of Service (COS) parameter in the LOGMODE for the host application.

SDLC nonswitched (leased) line connection

Dedicated point-to-point lines operate at speeds from 4,800 to 2,048,000 bps. You can lease dedicated lines from a phone company or install them in a single building or business. You can use either a modem or DSU/CSU, depending on whether the dedicated line is analog or digital.

SDLC Nonswitched (Leased) Line Connection

SDLC leased lines use modems or DSU/CSUs to answer remote phone calls.

The BARR/SNA SDLC Link Service configuration utility and the SDLC Connection Configuration dialog box are used to configure the SDLC link service for the BARR/RJE software. The parameters specified are also used by NCP on the mainframe. Your host programmer can provide you with the correct parameter values. After you enter the communication link parameters in the software, BARR/RJE produces a sample of the statement the host programmer needs to enter in the host NCP parameter library. You can view and print this statement by clicking NCP on the Communication Link tab.

NCP definition for SDLC nonswitched (leased) line

NCP Definition for Nonswitched Line Dialog Box

GROUP macro

The GROUP macro instruction gives common parameter settings for all LINE macros in the group.

group

GROUP DIAL=No,LNCTL=SDLC

Required parameters

Parameter

Description

group

Optional macro label.

DIAL=NO

Indicates a dedicated line.

LNCTL=SDLC

Indicates the line control is SDLC.

LINE macro

The LINE macro defines the line at the host and is necessary for SDLC connections.

linename LINE

ADDRESS=(aaa,FULL),DUPLEX=FULL,

X

 

NRZI=Yes,RETRIES=(8,2,20),SPEED=nnnnnn,TRANSFR=16

 

Required parameters

Parameter

Description

linename

The VTAM name of the communications line.

ADDRESS=(aaa,FULL)

Indicates the line interface address, aaa, when you select DATMODE=FULL on the SDLC Connection Configuration dialog box and the VTAM PU definition.

To maximize performance, when you set ADDRESS to FULL and there is only one address on the line (this is not a multidrop line), VTAM automatically keeps RTS high at all times. This setting also helps improve performance, especially on high-speed lines.

DUPLEX=FULL

The line and modem can send and receive data simultaneously.

NRZI=YES|NO

NRZI is a method to encode binary data over a serial interface. Check if your host uses NRZI encoding.

YES – Use NRZI encoding. Use this option if frequent SDLC aborts occur.

NO – Do not use NRZI encoding.

RETRIES=(m,t,n)

The number of attempts the system will make to recover from communications errors.

m – Maximum retransmissions of a frame while waiting for a normal response. The recommended value is 8.

t – Time in seconds paused after m retransmissions have failed. The recommended value is 2.

n – Number of times the above error recovery sequence is repeated. The recommended value is 20.

SPEED=nnnnnn

Required. Because the modem provides the bits-per-second clock, this parameter has no effect on BARR/RJE functions. The IBM Network Performance Monitor uses this value to calculate statistics.

TRANSFR=16

The number of NCP buffers. This value corresponds to the maximum amount of data (the data transfer limit) that NCP will receive from the line during a single data transfer operation.

System default values

Parameter

Description

CHECK=NODCD

The DCD line from the modem will not be monitored.

CLOCKNG=EXT

External clocking indicates that the modem’s clock controls the transmission rate.

SERVICE macro

The SERVICE macro controls the order in which the PUs get serviced on a dedicated line.

service

SERVICE ORDER=(puname)

Required parameters

Parameter

Description

service

The name of the SERVICE macro is arbitrary. You can have multiple SERVICE statements with the same name.

ORDER=(puname)

The operands in the ORDER list give the order in which the PUs will be polled on a multipoint line. You can preferentially service one of the PUs on a multipoint line by listing it more than once in the ORDER list.

PU macro

The PU macro names and describes a PU. You can operate several PUs on the same line (multipoint). Each unit requires a separate PU macro instruction.

puname PU

ADDR=C1,DATMODE=FULL,

X

 

MAXDATA=1033,MAXOUT=7,

X

 

PACING=7,PASSLIM=7,VPACING=7

 

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

ADDR=aa

The 8-bit address used by SDLC. This address, the first byte of every frame, separates messages sent to different PUs on the same line.

DATMODE=FULL|HALF

Specify whether the PU data mode is full or half duplex.

FULL – Default. The system sends and receives data simultaneously resulting in up to twice the normal throughput. The V.32 modem standard supports full duplex on dial-up lines. Some modems do not support full-duplex communications.

If you select DATMODE=FULL on the SDLC Connection Configuration dialog box, the host programmer must also specify it at the host. If the computer and host settings do not match, the software might have communication problems such as timeouts or lowered performance when it sends data to the host.

HALF – In half duplex, the communications line is either in a send or receive mode, so less than half the capacity of the line is available for use.

To maximize performance, specify DATMODE=FULL on the SDLC Connection Configuration dialog box and the VTAM PU definition. You can achieve maximum BARR/RJE performance with full-duplex mode. Full duplex enables you to send and receive data simultaneously, often doubling throughput. You can even improve one-way throughput because you can receive acknowledgments while you send data.

MAXDATA=265|521|1033|2057

The maximum amount of data you can send on the PU in one frame. This value includes nine bytes of header information plus the data length. The default value is 1033.

To maximize performance, you can increase throughput by sending larger frames of data. Send 1024 bytes by setting MAXDATA to 1033 on the SDLC Connection Configuration dialog box and the VTAM PU definition. This step reduces the amount of control information and total number of frames sent. A MAXDATA value of 2057 can result in greater system throughput, but it is not recommended for Ethernet or other LAN equipment that will not support the larger packet size.

MAXOUT=n

Specifies that up to n frames of information can be sent before waiting for a response. The maximum MAXOUT value of 7 will result in the highest throughput.

PACING=n

Determines how much data to send to BARR/RJE before a pacing response is needed to send more data. Pacing is a flow-control mechanism that prevents the host from sending data faster than BARR/RJE can print or otherwise handle it. Values smaller than the MAXOUT parameter often lower performance.

PASSLIM=n

The maximum number of information frames sent to the PU at one time, which is usually set to the same value as MAXOUT.

VPACING=n

Similar to the PACING parameter, but VPACING determines pacing between the RJE system and VTAM. VPACING is usually set to the same value as MAXOUT.

To maximize performance, setting parameters to larger values can improve BARR/RJE performance. With PACING=7 and VPACING=7 in the VTAM PU definition, the host can send 7 data frames before it requires a pacing response. On a half-duplex line, the host sends 7 frames at a time. When you use PACING=7, the pacing response could be returned in time for you to send 7 more frames of data. Include MAXOUT=7 in the PU definition.

System default values

Parameter

Description

DISCNT=(NO)

Do not disconnect the PU until BARR/RJE requests it.

ISTATUS=ACTIVE

The PU will be activated automatically.

PUTYPE=2

BARR/RJE uses the PU Type 2 protocol.

Other useful parameters

Parameter

Description

DLOGMOD=nnnnnnnn

Specify the logon mode table entry to use by default.

MODETAB=nnnnnnnn

Specify the mode table containing the logmode entries. ISTINCLM is the default IBM-supplied mode table usually present with VTAM.

SSCPFM=USSSCS

If this parameter is set, then the host's logon type and the Logon type selected on the RJE Description tab, must be configured as Character Coded. The system default is SSCPFM=FSS, which indicates that the Logon type must be Formatted.

LU macro

The LU macro instruction defines LUs allocated to the RJE devices.

luname02 LU

LOCADDR=2,BATCH=YES

**  RJE  LU

Use the LU macro formula to calculate the number of LUs you need.

Required parameters

Parameter

Description

lunamenn

The LU name conforms to the naming convention at your site. BARR/RJE does not use this name.

LOCADDR=i

The local addresses must be unique. The maximum value for i is 20 when you use Barr software. MVS/JES2 supports a maximum of 13 LUs.

BATCH=YES

Indicates the processing priority. Batch applications, such as RJE, require low priority. While interactive applications, such as 3270, usually have higher priority.

For VTAM Version 4, Release 3 or later, this parameter is replaced by the Class of Service (COS) parameter in the LOGMODE for the host application.

802.2 LLC2 connections

As shown in the following graphic, the 3725 and 3745 front-end processors (FEPs) attach to an 802.2 network through a TIC.

802.2 LLC2 Connections

FEPs attach to an 802.2 network through TICs.

The BARR/SNA 802.2 Link Service configuration utility and the 802.2 Connection Configuration dialog box are used to configure the 802.2 LLC2 link service for the BARR/RJE software. The parameters specified are also used by VTAM and NCP on the mainframe. Your host programmer can provide you with the correct parameter values. After you enter the communication link parameters in the software, BARR/RJE produces samples of the statements the host programmer needs to enter in the host VTAM and NCP parameter libraries. You can view and print these statements by clicking NCP and Physical Unit on the Communication Link tab.

NCP definition for 802.2

The following is the recommended NCP definition for an 802.2 LLC2 connection. You can access this dialog box by clicking NCP on the Communication Link tab. The parameters that appear in the dialog box vary depending on the settings configured in the BARR/RJE software. The parameters that change are displayed in blue text.

NCP Definition for 802.2 Dialog Box

GROUP macro for physical group

The GROUP macro instruction for the physical group includes common parameter settings for all LINE macros in the group.

group

GROUP ECLTYPE=PHYSICAL

Required parameters

Parameter

Description

group

Optional macro label.

ECLTYPE=PHYSICAL

This GROUP macro defines a physical connection to the 802.2 LLC2.

LINE macro

The LINE macro defines the line at the host.

linename LINE

ADDRESS=(aaaa,FULL),LOCADD=400000000001,

X

 

PORTADD=pp,RCVBUFC=4095

 

Required parameters

Parameter

Description

linename

The VTAM name of the communications line.

ADDRESS=(aaaa,FULL)

Specifies the logical address for the network card in the NCP where aaaa is the address.

LOCADD=4000abbbbbbb

The locally administered address for the network card for the host where a is a digit from 0 to 7 and b is a hexadecimal digit from 0 to F.

PORTADD=pp

The port number pp that associates a physical line with a logical line. The number must be the same as the PHYPORT parameter on the logical line.

RCVBUFC=4095

This parameter sets the maximum amount of data the host can receive from the 802.2 LLC2 link.

GROUP macro for logical group

The GROUP macro for the logical group defines a logical connection to the 802.2 network.

group

GROUP ECLTYPE=LOGICAL,AUTOGEN=100,

X

 

CALL=INOUT,PHYPORT=pp

 

Required parameters

Parameter

Description

group

Optional macro label.

ECLTYPE=LOGICAL

This GROUP macro defines a logical connection to the 802.2 LLC2.

AUTOGEN=100

The number of lines and groups supported by NCP.

CALL=INOUT

Both VTAM and BARR/RJE can initiate the connection.

PHYPORT=pp

The port number pp that associates a physical line with a logical line. The number must be the same as the PORTADD parameter on the physical line.

PU macro

The PU macro names and describes a physical unit. The PU macro in the NCP definition is replaced at log on with the PU macro from VTAM.

puname

PU

MAXLU=5

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

MAXLU=n

The maximum number of LUs to use with this line. Use the LU macro formula to calculate the number of LUs you need. If you are upgrading from DOS-based BARR/RJE, the number of Non-RJE LUs specified on the Communication Link tab is also included in the calculation.

PU definition for 802.2

The following is the recommended PU definition for an 802.2 LLC2 connection. You can access this dialog box by clicking Physical Unit on the Communication Link tab. The parameters that appear in the dialog box vary depending on the settings configured in the BARR/RJE software. The parameters that change are displayed in blue text.

PU Definition for 802.2 Dialog Box

PU macro

The PU macro names and describes a physical unit.

puname PU

ADDR=01,

X

 

IDBLK=03D,

X

 

IDNUM=12345,

X

 

MAXDATA=1033,

X

 

PACING=7,PASSLIM=7,VPACING=7

 

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

ADDR=01

Required.

IDBLK=bbb
IDNUM=nnnnn

Parameters used on an 802.2 network to identify the remote’s PU definition. During Xid negotiation, the remote sends an Exchange ID that contains the IDBLK and IDNUM parameters. VTAM searches for the PU identified by IDBLK and IDNUM and uses this PU for the rest of the communications session.

MAXDATA=265|521|1033|2057

The maximum amount of data you can send on the PU in one frame. This count includes nine bytes of header information plus the data length. The default value is 1033.

To maximize performance, you can increase throughput by sending larger frames of data and thus reduce the amount of control information and total number of frames sent. Send 1024 bytes by setting MAXDATA to 1033 on the 802.2 Connection Configuration dialog box and VTAM PU definition. Setting MAXDATA to 2057 can result in greater system throughput, but it is not recommended for Ethernet or other LAN equipment that will not support the larger packet size.

PACING=n

Determines how much data the host sends to BARR/RJE before it needs a pacing response to send more data. Pacing is a flow-control mechanism that prevents the host from sending data faster than BARR/RJE can print or otherwise handle it. Values smaller than 7 often lower performance.

PASSLIM=n

The maximum number of information frames sent to the PU at one time.

VPACING=n

Similar to the PACING parameter, but VPACING determines pacing between the RJE system and VTAM. Values less than 7 lower efficiency.

To maximize performance, setting parameters to larger values can improve BARR/RJE performance. With PACING=7 and VPACING=7 in the VTAM PU definition, the host can send 7 data frames before it requires a pacing response. On a half-duplex line, it sends 7 frames at a time. When you use PACING=7, the pacing response could be returned in time to send 7 more frames of data.

System default values

Parameter

Description

DISCNT=(NO,F)

Does not disconnect the PU until requested by BARR/RJE.

ISTATUS=ACTIVE

Automatically activates the PU.

PUTYPE=2

BARR/RJE uses the Physical Unit Type 2 protocol.

Other useful parameters

Parameter

Description

DLOGMOD=nnnnnnnn

Names the logon mode table entry to use by default.

MODETAB=nnnnnnnn

Specifies the mode table containing the logmode entries. ISTINCLM is the default IBM-supplied mode table usually present with VTAM.

SSCPFM=USSSCS

If this parameter is set, then the host's logon type and the Logon type selected on the RJE Description tab, must be configured as Character Coded. The system default is SSCPFM=FSS, which indicates that the Logon type must be Formatted.

LU macro

The LU macro instructions define LUs allocated to the RJE devices.

luname02 LU

LOCADDR=2,

**  RJE  LU

luname03 LU

LOCADDR=3,

**  RJE  LU

luname04 LU

LOCADDR=4,

**  RJE  LU

luname05 LU

LOCADDR=5,

**  RJE  LU

luname06 LU

LOCADDR=6,

**  RJE  LU

Use the LU macro formula to calculate the number of LUs you need.

Required parameters

Parameter

Description

lunamenn

The LU name conforms to the naming convention at your site. BARR/RJE does not use this name.

LOCADDR=i

The local addresses must be unique. The maximum value for i is 20 when you use Barr software. MVS/JES2 supports a maximum of 13 LUs with BARR/RJE.

HPR/IP (Enterprise Extender) connections

As shown in the following graphic, HPR/IP uses any interface network card, such as Ethernet One of the LAN physical standards. It allows multiple stations to access the transmission medium. to connect to the mainframe.

HPR/IP Connections

HPR/IP connections connect to the mainframe using IP.

The BARR/SNA HPR/IP Link Service configuration utility and the HPR/IP Connection Configuration dialog box are used to configure the HPR/IP link service for the BARR/RJE software. The parameters specified are also used by VTAM on the mainframe. Your host programmer can provide you with the correct parameter values. After you enter the communication link parameters in the software, BARR/RJE produces a sample of the statements the host programmer needs to enter in the host VTAM parameter library. You can view and print these statements by clicking Physical Unit on the Communication Link tab.

For HPR/IP connections, you must perform additional TCP/IP and VTAM configuration.

PU definition

The following is the recommended PU definition for an HPR/IP connection. You can access this dialog box by clicking Physical Unit on the Communication Link tab. The parameters that appear in the dialog box vary depending on the settings configured in the BARR/RJE software. The parameters that change are displayed in blue text.

PU Definition for HPR/IP Dialog Box

PU macro

The PU macro names and describes a physical unit.

puname PU

ADDR=01,

X

 

IDBLK=03D,

X

 

IDNUM=12345,

X

 

MAXDATA=1033,

X

 

PACING=7,PASSLIM=7,VPACING=7

 

Required parameters

Parameter

Description

puname

The PU’s name conforms to the naming convention at your site. The VTAM operator uses the name to vary the unit active or inactive and to query the unit’s status.

ADDR=01

Required.

IDBLK=bbb
IDNUM=nnnnn

Parameters used on an IP network to identify the remote’s PU definition. During Xid negotiation, the remote sends an Exchange ID that contains the IDBLK and IDNUM parameters. VTAM searches for the PU identified by IDBLK and IDNUM and uses this PU for the rest of the communications session.

MAXDATA=265|521|1033|2057

The maximum amount of data you can send on the PU in one frame. This count includes nine bytes of header information plus the data length. The default value is 1033.

To maximize performance, you can increase throughput by sending larger frames of data and thus reduce the amount of control information and total number of frames sent. Send 1024 bytes by setting MAXDATA to 1033 on the HPR/IP Connection Configuration dialog box and VTAM PU definition. Setting MAXDATA to 2057 can result in greater system throughput, but it is not recommended for Ethernet or other LAN equipment that will not support the larger packet size.

PACING=n

Determines how much data the host sends to BARR/RJE before it needs a pacing response to send more data. Pacing is a flow-control mechanism that prevents the host from sending data faster than BARR/RJE can print or otherwise handle it. Values smaller than 7 often lower performance.

PASSLIM=n

The maximum number of information frames sent to the PU at one time.

VPACING=n

Similar to the PACING parameter, but VPACING determines pacing between the RJE system and VTAM. Values less than 7 lower efficiency.

To maximize performance, setting parameters to larger values can improve BARR/RJE performance. With PACING=7 and VPACING=7 in the VTAM PU definition, the host can send 7 data frames before it requires a pacing response. On a half-duplex line, it sends 7 frames at a time. When you use PACING=7, the pacing response could be returned in time to send 7 more frames of data.

System default values

Parameter

Description

DISCNT=(NO,F)

Does not disconnect the PU until requested by BARR/RJE.

ISTATUS=ACTIVE

Automatically activates the PU.

PUTYPE=2

BARR/RJE uses the Physical Unit Type 2 protocol.

Other useful parameters

Parameter

Description

DLOGMOD=nnnnnnnn

Names the logon mode table entry to use by default.

MODETAB=nnnnnnnn

Specifies the mode table containing the logmode entries. ISTINCLM is the default IBM-supplied mode table usually present with VTAM.

SSCPFM=USSSCS

If this parameter is set, then the host's logon type and the Logon type selected on the RJE Description tab, must be configured as Character Coded. The system default is SSCPFM=FSS, which indicates that the Logon type must be Formatted.

LU macro

The LU macro instructions define LUs allocated to the RJE devices.

luname02 LU

LOCADDR=2,

**  RJE  LU

luname03 LU

LOCADDR=3,

**  RJE  LU

luname04 LU

LOCADDR=4,

**  RJE  LU

luname05 LU

LOCADDR=5,

**  RJE  LU

luname06 LU

LOCADDR=6,

**  RJE  LU

Use the LU macro formula to calculate the number of LUs you need.

Required parameters

Parameter

Description

lunamenn

The LU name conforms to the naming convention at your site. BARR/RJE does not use this name.

LOCADDR=i

The local addresses must be unique. The maximum value for i is 20 when you use Barr software. MVS/JES2 supports a maximum of 13 LUs with BARR/RJE.