HiperSockets concepts and connectivity

HiperSockets is a System z® hardware feature that provides high performance internal communications between LPARs within the same central processor complex (CPC), without the use of any additional or external hardware equipment (for example, channel adapters and LANs). When the processor supports HiperSockets and the CHPIDs are configured in HCD (IOCP), TCP/IP connectivity can occur for two reasons:

  • DYNAMICXCF is configured on the IPCONFIG (IPv4) or the IPCONFIG6 (IPv6) statements.
  • A user-defined HiperSockets (MPCIPA) DEVICE and LINK (IPv4) or INTERFACE (IPv4 or IPv6) is configured and started.

Therefore, there are two types of HiperSockets devices:

  • DYNAMICXCF HiperSockets device or interface (TRLE IUTIQDIO and an MPC group of subchannel devices)

    The PORTNAME is IUTIQDxx, where xx is the IQD CHPID that VTAM® uses (for example, IUTIQDFD when using IQD CHPID x'FD').

  • A user-defined HiperSockets device or interface consisting of an MPC group of subchannel devices and one of the following definitions:
    • TRLE IUTIQDxx for INTERFACE (IPv6) and DEVICE/LINK (IPv4)
    • TRLE IUTIQ4xx for INTERFACE (IPv4)

    The PORTNAME is not applicable for these TRLEs.

When HiperSockets is configured with a DEVICE and LINK definition, the z/OS® TCP/IP stack has only one connection to the HiperSockets CHPID. You define this connection with a combination of the DEVICE, LINK, and HOME statements for IPv4, an INTERFACE statement for IPv6, or both. This single connection uses one DATAPATH device from the TRLE definition that VTAM creates to represent this HiperSockets CHPID. Both IPv4 and IPv6 traffic share this one connection and DATAPATH device. For more information about DATAPATH devices and TRLEs, see z/OS Communications Server: SNA Network Implementation Guide.

If you configure a HiperSockets CHPID for IPv4 using the INTERFACE statement and also configure the same HiperSockets CHPID for IPv6, then the z/OS TCP/IP stack has two connections to the OSA-Express® feature and requires two DATAPATH devices.