Planning for IQD CHPID spanning

Figure 1 illustrates how an IQD CHPID can span both logical channel subsystem 0 and logical channel subsystem 1.

Figure 1. Spanned IQD (HiperSockets) CHPID

In Figure 1, note:

• CHPID spanning is applicable to servers that support multiple channel subsystems, such as the IBM® z990 server.
• IQD CHPIDs and their spanning attributes are configured using HCD.
• Logical channel subsystem 0 and logical channel subsystem 1 are both using IQD CHPID F2, which was configured (in HCD) to span.
• All images can exploit IQD CHPID spanning.
• Using HiperSockets™ support along with IQD spanning support, logical partitions in both logical channel subsystem 0 and 1 have internal connectivity.
• Specific logical partitions can be configured to have access to the spanned IQD CHPID. In this example:
  • IQD CHPID F2 is configured to span both logical channel subsystem 0 and logical channel subsystem 1.
  • In logical channel subsystem 0, zOS1 and zVM1 have connectivity (through IQD CHPID F2) to zOS3 and zOS4 in logical channel subsystem 1.
  • zOS2 and zVM2 do not have access to IQD CHPID F2.
• Up to 16 IQD CHPIDs can be configured in HCD.
• There are no TCP/IP or VTAM® configuration changes required (spanning support is transparent to z/OS® Communications Server).
  Tip: TCP/IP Dynamic XCF support uses HiperSockets connectivity when the remote system is reachable through HiperSockets. This is dynamically determined, and this internal logic also handles a spanned IQD CHPID.

To configure a spanned IQD CHPID, see z/OS HCD User's Guide.