Network adapters

Several types of network adapters enable communication through different networking transport protocols.

These network adapters are:
  • Open Systems Adapter-Express (OSA-Express) adapters, which provide direct, industry-standard Ethernet LAN connectivity through various operational modes and protocols. OSA adapters can provide connectivity between partitions on the same system, as well as connectivity to external LANs.

    The supported OSA adapters vary, depending on the system configuration; for example, the z14 supports the OSA-Express6S, OSA-Express5S, and OSA-Express4S adapters.

  • HiperSockets, which are virtual adapters that provide high-speed communications between partitions within a single system, without the need for any physical cabling or external networking connections. Each HiperSocket adapter represents a single internal network, and only those partitions with access to that adapter participate in that network.
  • Remote Direct Memory Access (RDMA) over Converged Ethernet (RoCE) Express adapters. These adapters provide high speed, low latency data transfer over Ethernet networks.

    The supported RoCE adapters vary, depending on the system configuration; for example, the z14 supports the 10 Gigabit Ethernet (GbE) RoCE Express2 and 10 GbE RoCE Express adapters.

For a list of the network adapters that are supported on a specific system, see the appropriate system technical guide on the IBM® Redbooks® web site at http://www.redbooks.ibm.com/.

DPM automatically discovers OSA and RoCE adapters because they are physical cards that are installed on the system. In contrast, HiperSockets are not physical adapters; you must configure them if you want to use them on your system. Depending on the DPM version that is installed on the system, use one of the following methods to create HiperSockets to interconnect partitions.
  • With DPM R5.1 or earlier, use the Create HiperSockets Adapter task, which is available through the Actions list on the Adapters tab of the Manage Adapters task.
  • With DPM R5.2, create and manage HiperSockets through the Configure Partition Links task, which provides a simplified and streamlined user experience for creating and managing HiperSockets connections.

Network interface cards (NICs) provide a partition with access to internal or external networks that are part of or connected to a system. Each NIC represents a unique connection between the partition and a specific network adapter that is defined or installed on the system.

Most systems have OSA adapters installed, and you will probably define a NIC to connect your partition to at least one of those OSA network connections. Your system planner or network administrator can advise you on which network connections to use for the workload that your partition supports. Network adapters provides a conceptual illustration of partitions that are configured to use different types of network adapters for access to internal and external networks.
  • Partitions A and B are both connected to the HiperSockets network within the DPM-enabled system, and to an OSA card for Ethernet access to an external network. (Depending on the DPM version that is installed on the system, you configure the NICs that the partitions use either through the Configure Partition Links task for a HiperSockets partition link, or through the Network section of the New Partition or Partition Details task.)
  • Partition C has only one NIC defined, for access to a RoCE adapter, which provides Ethernet access between the DPM-enabled system and one other system in the network.
  • If partitions A and B share the same OSA adapter or HiperSockets connection, you can create an SMC-D partition link (not shown in the figure) to attach to both partitions. Shared Memory Communications - Direct Memory Access (SMC-D) provides high-bandwidth, low-latency TCP/IP traffic over internal shared memory (ISM) devices for improved performance. For more information, see SMC-D partition links.
Figure 1. Partitions with NICs configured for access to network adapters on a DPM-enabled system
This diagram illustrates several partitions with network interface cards that connect the partition to network adapters