.-IQDCHPID--=--ANY-------. >>-+------------------------+---------------------------------->< '-IQDCHPID--=--+-ANY---+-' +-NONE--+ '-chpid-'
IQDCHPID = chpid specifies the (hexadecimal) CHPID (Channel Path ID) that is to be used for HiperSockets™ communications from this LP (Logical Partition) to other LPs within this central processor complex (CPC) for TCP/IP Dynamic XCF support. This start option allows the user to designate or reserve a specific IQD CHPID for use by dynamic XCF HiperSockets. This option does not affect user defined HiperSockets devices. HiperSockets is used for TCP/IP Dynamic XCF support. All instances of TCP/IP started within this z/OS® Communications Server LP will use this same CHPID Dynamic XCF HiperSockets device. VTAM® will dynamically construct an HiperSockets TRLE using the HiperSockets subchannel devices associated with this CHPID. The dynamic TRLE created will have a name of IUTIQDIO.
A TRLE that has the reserved name IUTIQDIO indicates it is the HiperSockets device that is built and used exclusively for dynamic XCF support. The PORTNAME will have a name of IUTIQDxx where xx = the iQD CHPID selected by VTAM. All LPs within this CPC using z/OS CS HiperSockets support that specify the same CHPID will gain internal connectivity by the way of dynamic XCF using HiperSockets. If the CPC is enabled to use multiple channel subsystems and the LPs are not using the same CSS channel subsystem, then the IQD CHPID must be defined (in HCD) to span the applicable CSSs. The CHPID is specified as a single hexadecimal byte or 2 digits (for example, F2). The IQDCHPID start option can also be modified. To understand the effects of modifications to IQDCHPID on an active system, see the IQDCHPID option of the MODIFY VTAMOPTS command in z/OS Communications Server: SNA Operation. This start option is valid only if the associated processor hardware support is available. When the processor support is not available, this start option is ignored and cannot be modified or displayed.
- IQDCHPID = ANY is the default and indicates that any HiperSockets CHPID can be used for the
Dynamic XCF HiperSockets device.
If ANY is specified or defaulted, then:
- When the first HiperSockets device is activated, VTAM will use the first acceptable HiperSockets CHPID detected (having at least 3 subchannel devices associated with the CHPID) to dynamically build the IUTIQDIO TRLE.
- Within HCD (or IOCDS), only one HiperSockets CHPID must be defined for this Logical Partition. If VTAM finds more than one HiperSockets CHPID, the HiperSockets activation will not be allowed (because it is considered an ambiguous definition). Users who require (and therefore define in HCD/IOCDS) a single HiperSockets CHPID for a given Logical Partition can use the default of ANY.
- IQDCHPID = NONE will prevent VTAM from activating the IUTIQDIO TRLE which is associated with Dynamic XCF HiperSockets device. The NONE option does not affect (block) the use of user defined HiperSockets devices. All subsequent attempts to activate HiperSockets from any TCP/IP stack within this LP will be prevented (rejected).
- IQDCHPID = chpid is the (hexadecimal) value for a specific HiperSockets (IQD) CHPID which is to be used to build the IUTIQDIO TRLE used only for Dynamic XCF. If the CHPID is specified, it must match one of the IQD CHPIDs that was also defined using HCD (or IOCDS). This LP must be eligible to connect to this specific CHPID and must have a minimum of three subchannel devices associated with this CHPID. The value must be specified as a single-byte hexadecimal number (for example, IQDCHPID=F2). This option is intended for users who must define multiple HiperSockets CHPIDs within HCD [for example, users who plan to use both dynamically defined HiperSockets devices (Dynamic XCF) and user defined HiperSockets devices].
- In order to use HiperSockets communications, this processor must have the necessary hardware support. This start option cannot be specified, modified, or displayed on a processor without the hardware support.
- HiperSockets activation requires a minimum of three subchannel devices and uses a maximum of ten subchannel devices. The HiperSockets subchannel devices associated with the selected iQD CHPID will be grouped together into a single MPC group (two read/write control devices and up to eight data devices). The subchannel devices must be online.