- ACCESSMETHOD({VTAM|INDIRECT|IRC|XM})
- specifies the access method to be used for this connection.
- VTAM
- Communication between the local CICS® region and the system defined by this
connection definition is through VTAM®. You can use VTAM intersystem communication
(ISC) for systems that are in different MVS™ images or in different address spaces
in the same MVS image.
- INDIRECT
- Communication between the local CICS system and the system defined by
this connection definition is through the system named in the INDSYS operand.
- IRC
- Communication between the local CICS region and the region defined by
this connection definition is through the interregion communication (IRC)
program DFHIRP, using the SVC (as opposed to cross-memory (XM)) mode of DFHIRP.
Note: This use of the term IRC is more specific than its general use.
You
can use IRC for multiregion operation (MRO) for regions that are in the same
MVS image or in different MVS images within a sysplex.
- XM
- MRO communication between the local CICS region and the region defined
by its CONNECTION definition uses MVS cross-memory services. Initial connection
is through the interregion communication (IRC) program DFHIRP, using the cross-memory
(XM) (as opposed to the SVC) mode of DFHIRP. You can use XM for multiregion
operation for regions that are in the same MVS image, or in different MVS
images within a sysplex.
Note: The CICS type 3 SVC is still required with
XM because DFHIRP is used when the link is opened. For further information
about SVCs, see
dfha111.html#dfha111 .
MVS
cross-memory services are used only if the ACCESSMETHOD of the other end of
the link is also defined as XM.
If the MRO partners reside in different MVS images within
a sysplex, and the CONNECTION specifies IRC or XM, CICS automatically uses
XCF as the access method, and ignores the IRC or XM specification.
- ATTACHSEC({LOCAL|IDENTIFY|VERIFY|PERSISTENT| MIXIDPE})
- specifies the level of attach-time user security required for the connection.
- IDENTIFY
- Incoming attach requests must specify a user identifier. Enter IDENTIFY
when the connecting system has a security manager; for example, if it is another
CICS system.
- LOCAL
- The authority of the user is taken to be that of the link itself, and
you rely on link security alone to protect your resource. If the PROTOCOL
attribute on the CONNECTION definition is LU6.1, you must specify LOCAL.
- MIXIDPE
- Incoming attach requests may be using either or both IDENTIFY or PERSISTENT
security types. The security type actually used depends on the incoming attach
request.
- PERSISTENT
- Incoming attach requests must specify a user identifier and a user password
on the first attach request. Subsequent attach requests require only the user
identifier. This should be used only between a programmable workstation, (for
example, an IBM® Personal
Computer) and CICS.
- VERIFY
- Incoming attach requests must specify a user identifier and a user password.
Enter VERIFY when the connecting system has no security manager and hence
cannot be trusted. Do not specify VERIFY for CICS-to-CICS communication, because
CICS does not send passwords.
- AUTOCONNECT({NO|YES|ALL})
- For systems using ACCESSMETHOD(VTAM), you specify with AUTOCONNECT(YES)
or (ALL) that sessions are to be established (that is, BIND is to be performed).
Such sessions are set up during CICS initialization, or when you use the CEMT
or EXEC CICS SET VTAM OPEN command to start communication with VTAM. If the
connection cannot be made at these times because the remote system is unavailable,
you must subsequently acquire the link by using the CEMT or EXEC CICS SET
CONNECTION(sysid) INSERVICE ACQUIRED command, unless the remote system becomes
available in the meantime and itself initiates communications.
For APPC
connections with SINGLESESS(NO) specified, CICS tries to bind, on system start-up,
the LU services manager sessions in mode group SNASVCMG.
For connection
definitions with SINGLESESS(YES) specified, the AUTOCONNECT operand is ignored.
Use the AUTOCONNECT operand of the session definition instead.
- ALL
- On this definition, ALL is equivalent to YES, but you can specify ALL
to be consistent with the session definition.
AUTOCONNECT(ALL) should
not be specified for connections to other CICS systems, because this can cause
a bind-race.
- NO
- CICS does not attempt to bind sessions when the connection is established.
- YES
- CICS attempts to bind only contention-winning sessions when the connection
is established.
The AUTOCONNECT option is not applicable on an LU6.1
connection definition. For LU6.1 connections, specify AUTOCONNECT(YES) on
the SESSIONS definition if you want the connection to be established at initialization
or CEDA install. Specify AUTOCONNECT(NO) on the SESSIONS definition if you
do not want the connection to be established at initialization or CEDA install.
- BINDPASSWORD
- This attribute is obsolete, but is supported to provide compatibility
with earlier releases of CICS. For more information, see Obsolete attributes.
- BINDSECURITY({NO|YES}) (APPC
only)
- specifies whether an ESM is being used for bind-time security.
- NO
- No external bind-time security is required.
- YES
- If security is active and the XAPPC system initialization parameter is
set to YES, CICS attempts to extract the session key from RACF® in order
to perform bind-time security. If no RACF profile is available, the bind fails.
- CONNECTION(name)
- specifies the name of this connection definition. The name can be up to
four characters in length.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
This
is the name specified as REMOTESYSTEM on file, terminal, transaction, and
program definitions. You should not have a terminal definition and a connection
definition with the same name.
- CONNTYPE({SPECIFIC|GENERIC})
- For external CICS interface (EXCI) connections, this specifies the nature
of the connection.
- GENERIC
- The connection is for communication from a non-CICS client program to
the CICS system, and is generic. A generic connection is an MRO link with
a number of sessions to be shared by multiple EXCI users. For a generic connection
you cannot specify the NETNAME attribute.
- SPECIFIC
- The connection is for communication from a non-CICS client program to
the CICS region, and is specific. A specific connection is an MRO link with
one or more sessions dedicated to a single user in a client program. For a
specific connection, NETNAME is mandatory.
- DATASTREAM({USER|3270|SCS|STRFIELD|LMS})
- specifies the type of data stream.
- LMS
- The data stream is a Logical Message Services (LMS) data stream consisting
of FMH4s and FMH8s as defined in the LUTYPE6.1 architecture.
- SCS
- The data stream is an SCS data stream as defined in the LUTYPE6.1 architecture.
- STRFIELD
- The data stream is a structured field data stream as defined in the LUTYPE6.1
architecture.
- USER
- Let DATASTREAM default to USER if the data stream is user-defined. If
you are communicating between multiple CICS systems, always let DATASTREAM
default to USER.
- 3270
- The data stream is a 3270 data stream as defined in the type 6.1 logical
unit (LUTYPE6.1) architecture.
- DESCRIPTION(text)
- You can provide a description of the resource you are defining in this
field. The description text can be up to 58 characters in length. There are
no restrictions on the characters that you can use. However,
if you use parentheses, ensure that for each left parenthesis there is a matching
right one. If you use the CREATE command, for each single apostrophe in the
text, code two apostrophes.
- GROUP(groupname)
- Every resource definition must have a GROUP name. The resource definition
becomes a member of the group and is installed in the CICS system when the
group is installed.
Acceptable characters:A-Z 0-9 $ @ #
Any
lower case characters you enter are converted to upper case. |
The GROUP name can be up to eight characters in length. Lowercase
characters are treated as uppercase characters. Do not use group names beginning
with DFH, because these characters are reserved for use by CICS.
- INDSYS(connection)
- specifies the name of another CONNECTION that defines an intermediate
system used to relay communications between this system and the remote system.
The name can be up to four characters in length.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
You may specify an intermediate system only if you specify
ACCESSMETHOD(INDIRECT).
- INSERVICE({YES|NO})
- specifies the status of the connection that is being defined.
- NO
- The connection can neither receive messages nor transmit input.
- YES
- Transactions may be initiated and messages may automatically be sent across
the connection.
- MAXQTIME({NO|seconds})
- specifies a time control on the wait time for queued allocate requests
waiting for free sessions on a connection that appears to be unresponsive.
The maximum queue time is used only if a queue limit is specified for QUEUELIMIT,
and then the time limit is applied only when the queue length has reached
the queue limit value.
- NO
- CICS maintains the queue of allocate requests that are waiting for a free
session. No time limit is set for the length of time that requests can remain
queued (though the DTIMOUT mechanisms can apply to individual requests). In
this case, a value of X'FFFF' is passed on the XZIQUE parameter list
(in field UEPEMXQT).
- seconds
- The approximate upper limit on the time that allocate requests can be
queued for a connection that appears to be unresponsive. The number represents
seconds in the range 0 through 9999.
CICS uses the maximum queue time
attribute to control a queue of allocate requests waiting. When the number
of queued allocate requests reaches the queue limit (QUEUELIMIT), and a new
allocate request is received for the connection, if the rate of processing
for the queue indicates that, on average, the new allocate takes more than
the maximum queue time, the queue is purged, and message DFHZC2300 is issued. When
the queue is purged, queued allocate requests return SYSIDERR.
No
further queuing takes place until the connection has successfully freed a
session. At this point, CICS issues DFHZC2301 and resumes normal queuing.
You can also control the queuing of allocate requests through
an XZIQUE global user exit program. This allows you to use statistics provided
by CICS, which report the state of the link. You can use these statistics,
in combination with the queue limit and maximum queue time values you specify,
to make more specialized decisions about queues.
The MAXQTIME value
is passed to an XZIQUE global user exit program on the XZIQUE parameter list,
if the exit is enabled. See the CICS Customization
Guide for programming information about writing an XZIQUE global
user exit program.
You can also specify the NOQUEUE|NOSUSPEND option
on the ALLOCATE command to prevent an explicit request being queued. See the CICS Application Programming Reference
for programming information about these API options.
- NETNAME(netname)
- specifies the network name that identifies the remote system. The name
can be up to eight characters in length. The name follows assembler language
rules. It must start with an alphabetic character.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
The NETNAME is the
APPLID of the remote system or region, unless you are defining an LUTYPE6.1
or APPC link to a VTAM generic resource group.
- If you are defining an LUTYPE6.1 link to a generic resource, NETNAME
must specify the generic resource name, not the APPLID of one of the group
members.
- If you are defining an APPC link to a generic resource, NETNAME can specify
either the group's generic resource name or the APPLID (member name) of one
of the group members. However, if you specify a member name, and this CICS
is not itself a member of a CICS generic resource, the connection must always
be acquired by this CICS ("this CICS " being the CICS region in which
the connection definition is installed).
For VTAM, the APPLID is the label of the remote VTAM VBUILD TYPE=APPL
statement.
If you do not supply a NETNAME, the CONNECTION name is used
by default.
There are some rules about duplicate NETNAMEs. You
cannot have:
- Two or more APPC links with the same NETNAME
- An APPC link and an LUTYPE6.1 link with the same NETNAME
- Two or more IRC connections with the same NETNAME
- Two or more remote APPC connections with the same NETNAME.
- A remote APPC connection with the same NETNAME as any other connection
or local terminal.
You
can have:
- An IRC connection and an LUTYPE6.1 connection with the same NETNAME
- An IRC connection and an APPC connection with the same NETNAME
- Two or more LUTYPE6.1 connections with the same NETNAME
- Any connection with the same NETNAME as a remote terminal.
For connections that use the VTAM LU alias facility: - APPC synclevel 1: If the CICS region supports VTAM dynamic LU alias
(that is, LUAPFX=xx is specified on the CICS region's
APPL statement) this NETNAME is assumed to be in the same network as the CICS
region. If it is not the resource must have a local VTAM CDRSC definition
with LUALIAS=netname defined, where netname must
match the NETNAME defined on this CONNECTION definition. Synclevel 1 APPC
connections are generally work stations.
Be aware that some synclevel 1
resources may become synclevel 2, depending on how they connect to CICS. For
example, if TXSeries does not use
a PPC gateway, the connection is synclevel 1. If it does use a PPC gateway,
it is synclevel 2.
- APPC synclevel 2 and LUTYPE6.1: This NETNAME is assumed to be
unique. CICS matches it against the network name defined in the VTAM APPL
statement. These connections are generally CICS-to-CICS but could, for example,
be TXSeries-connected through a PPC gateway.
- PROTOCOL({APPC|LU61|EXCI|blank})
- specifies the type of protocol that is to be used for the link.
- APPC (LUTYPE6.2 protocol)
- Advanced program-to-program communication, or APPC protocol. This is the
default value for ACCESSMETHOD(VTAM). Specify this for CICS-CICS ISC.
- blank
- MRO between CICS regions. You must leave the PROTOCOL blank for MRO, and
on the SESSIONS definition you must specify LU6.1 as the PROTOCOL.
- EXCI
- The external CICS interface. Specify this to indicate that this connection
is for use by a non-CICS client program using the external CICS interface.
- LU61
- LUTYPE6.1 protocol. Specify this for CICS-CICS ISC or CICS-IMS™ ISC, but not
for MRO.
- PSRECOVERY({SYSDEFAULT|NONE})
- In a CICS region running with persistent sessions support, this specifies
whether, and how, LU6.2 sessions are recovered on system restart within the
persistent session delay interval.
- NONE
- All sessions are unbound as out-of-service with no CNOS recovery.
- SYSDEFAULT
- If a failed CICS system is restarted within the persistent session delay
interval, the following actions occur:
- User modegroups are recovered to the SESSIONS RECOVOPTION value.
- The SNASVCMG modegroup is recovered.
- The connection is returned in ACQUIRED state and the last negotiated CNOS
state is returned
- QUEUELIMIT({NO|number})
- specifies
the maximum number of allocate requests that CICS is to queue while waiting
for free sessions:
- NO
- There is no limit set to the number of allocate requests that CICS can
queue while waiting for a free session. In this case, a value of X'FFFF' is
passed on the XZIQUE parameter list (in field UEPQUELM).
- number
- The maximum number of allocate requests, in the range 0 through 9999,
that CICS can queue on the connection while waiting for a free session. When
the number of queued allocate requests reaches this limit, subsequent allocate
requests return SYSIDERR until the queue drops below the limit.
This queue
limit is passed to an XZIQUE global user exit program on the XZIQUE parameter
list if the exit is enabled.
You can also control the queuing of allocate requests through
the MAXQTIME attribute, and through an XZIQUE global user exit program. See
the MAXQTIME attribute for more information about controlling queues.
Note: BIND
re-negotiation is not triggered, even if there are unused secondary sessions.
Unless the CEMT SET MODE command is used to force re-negotiation, the queuelimit
will come into play as soon as all the primary sessions are in use.
- RECORDFORMAT({U|VB})
- specifies the type of SNA chain.
- U
- Let RECORDFORMAT default to U if the SNA chain is a single, unblocked
stream of data. You can have private block algorithms within the SNA chain.
Let RECORDFORMAT default to U if you are communicating between multiple CICS
systems.
- VB
- The SNA chain is formatted according to the VLVB standard as defined in
the LUTYPE6.1 architecture.
- REMOTENAME(connection)
- specifies the name by which the APPC connection for transaction routing
is known in the system or region that owns the connection. The name can be
up to four characters in length.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
The remote system or region can be an APPC device (see APPC devices for transaction routing).
- REMOTESYSNET(netname)
- specifies the network name (APPLID) of the system that owns the connection.
The name can be up to eight characters in length. It follows assembler language
rules, and must start with an alphabetic character.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
Use REMOTESYSNET
when transaction routing to remote APPC systems or devices, and there is no
direct link between the region in which this definition is installed and the
system that owns the connection to the remote device. You do not need to specify
REMOTESYSNET if:
- You are defining a local connection (that is, REMOTESYSTEM is not specified,
or specifies the sysid of the local system).
- REMOTESYSTEM names a direct link to the system that owns the connection.
However, there is one special case: if the connection-owning region is a
member of a VTAM generic resources group and the direct link to it is an APPC
connection, you may need to specify REMOTESYSNET. REMOTESYSNET is needed in
this case if the NETNAME specified on the CONNECTION definition for the direct
link is the generic resource name of the connection-owning region (not the
applid).
- REMOTESYSTEM(connection)
- specifies the name that identifies the intercommunication link to the
system that owns the connection. The name can be up to four characters in
length.
Acceptable characters:A-Z 0-9 $ @ #
Unless
you are using the CREATE command, any lowercase characters you enter are converted
to uppercase. |
This
is the CONNECTION name on the connection definition for the intercommunication
link.
REMOTESYSTEM is used for transaction routing to remote APPC systems
or devices. If it is not specified, or if it is specified as the sysid of
the local system, this connection is local to this system. If the name is
that of another system, the connection is remote. You can therefore use the
same definition for the connection in both the local system and a remote system.
If
there are intermediate systems between this CICS and the region that owns
the (connection to the) device, REMOTESYSTEM should specify the first link
in the path to the device-owning region. If there is more than one possible
path, it should specify the first link in the preferred path.
- SECURITYNAME(userid)
- For APPC and LU6.1 links only, this is the security name of the remote
system.
In a
CICS system with security initialized (SEC=YES), the security name is used
to establish the authority of the remote system.
Note: If USERID is specified
in the
SESSIONS definition
associated with the connection definition, it overrides the userid specified
in the SECURITYNAME attribute, and is used for link security.
The
security name (or USERID on the sessions definition) must be a valid RACF
userid on your system. Access to protected resources on your system is based
on the RACF user profile and its group membership.
- SINGLESESS({NO|YES})
- specifies whether the definition is for an APPC terminal on a single session
APPC link to CICS.
- NO
- The definition is not for a single session APPC link to CICS.
- YES
- The definition is for an APPC terminal on a single session APPC link to
CICS.
The MODENAME attribute of the SESSIONS definition can be
used to supply a modename for the single session mode set.
An APPC
single session terminal can also be defined as a TERMINAL-TYPETERM definition.
Both the TERMINAL-TYPETERM definition and the CONNECTION definition can be
autoinstalled. If you are considering using autoinstall, see Autoinstalling VTAM terminals.
- USEDFLTUSER ({NO|YES}) (APPC
and MRO only)
- specifies
the action that is taken when an inbound FMH5 does not contain the security
information implied by the ATTACHSEC attribute.
- NO
- The attach request is rejected, and a protocol violation message is issued.
- YES
- The attach is accepted, and the default
user ID is associated with the transaction.
For more information, see the CICS RACF Security
Guide and CICS RACF Security
Guide.
- XLNACTION({KEEP|FORCE}) (APPC
and MRO only)
- specifies the action to be taken when a new logname is received from
the partner system. Receipt of a new logname indicates that the partner has
deleted its recovery information.
Note: MRO here covers connections with
ACCESSMETHOD set to either IRC or XM.
- FORCE
- The predefined decisions for in-doubt UOWs (as defined by the indoubt
attributes of the transaction definition) are implemented, before any new
work with the new logname is started. CICS also deletes any information retained
for possible resolution of UOWs that were in-doubt at the partner system.
Attention: Data integrity may be compromised if you use this option.
- KEEP
- Recovery information is kept, and no action is taken for in-doubt units
of work.
For IRC, the connection continues with new work. Resolve
in-doubt UOWs using the CEMT or SPI interface.
For APPC, the
connection is unable to perform new work that requires synclevel 2 protocols
until all outstanding recoverable work with the partner (that is, in-doubt
UOWs, or information relevant to UOWs that were in-doubt on the partner system
under the old logname) is completed using the CEMT or SPI interface.
Note: On IRC connections to pre-
CICS Transaction Server for z/OS® systems,
and on LU6.1 connections to all levels of CICS, lognames are not used and
the XLNACTION attribute is ignored. For detailed information about IRC connections
to back-level systems, see
the CICS Intercommunication
Guide.