Strengthening the fabric of the on demand operating environment

OSA-Express for Ethernet connectivity to local area networks (LANs)

IBM mainframes provide an advanced combination of reliability, availability, security, scalability and virtualization, together with the ability to reallocate processing power matching changing business priorities on demand.

Continual advances in hardware and TCP/IP networking capabilities reinforce the integral role of the mainframe in your on demand operating environment. The Open Systems Adapter-Express (OSA-Express) family of features, for Ethernet connectivity to the local area network (LAN), are designed to help satisfy the requirements of bandwidth-hungry applications.

OSA-Express5S an Ethernet technology refresh

A new generation of Ethernet features is being introduced for use in the Peripheral Component Interconnect Express Generation 2 (PCIe Gen2) I/O drawer which is supported by an 8 GBps PCIe Gen2 host bus. This is an introduction of the full family of features – 1000BASE-T Ethernet for copper cabling environments, in addition to 10 Gigabit (10 GbE) and Gigabit Ethernet (GbE) for single mode (LR/LX features) and multimode (SR/SX features) fiber optic cabling environments. For the first time, small form factor pluggable+ (SFP+) transceivers are being introduced. The performance characteristics are comparable to the OSA-Express4S features. Refer to the What’s New tab for more information. OSA-Express5S is exclusive to the IBM zEnterprise EC12 (zEC12) and IBM zEnterprise BC12 (zBC12) servers.

PCIe I/O drawer - increased capacity, granularity, bandwidth, and RAS

The PCIe I/O drawer supports the OSA-Express5S and OSA-Express4S features, providing you with increased capacity, granularity, and infrastructure bandwidth, as well as increased reliability, availability, and serviceability compared to the I/O drawer or I/O cage.

Capacity: With their compact design, two PCIe I/O drawers occupy the same space as one I/O cage while delivering 14% more capacity - up to 128 channels (64 I/O cards) are supported versus the 112 channels (28 I/O cards) offered with the I/O cage.

Granularity: With the PCIe I/O drawer comes enhanced granularity Ethernet features for the local area network (LAN).

Increased infrastructure bandwidth: The industry-standard Peripheral Component Interconnect Express Generation 2 (PCIe Gen2) infrastructure from the processor book or processor drawer to the I/O cards, is designed to support an 8 gigabytes per second (8 GBps) bus. This infrastructure is designed to offer enhanced bandwidth in the connection to the processor book or processor drawer as well as the distribution buses contained in the drawer.

Reliability, Availability, Serviceability (RAS): The PCIe I/O drawer is designed with symmetrical, redundant cooling across all I/O cards and power supplies for improved RAS. Dual PCIe paths to the system processors from an I/O card provide enhanced resiliency. Also included are temperature monitoring of critical ASICs to optimize cooling and reliability.

HiperSockets for virtual LANs between logical partitions within a IBM z Systems

The HiperSockets function, also known as internal queued direct input/output (internal QDIO or iQDIO), is an integrated function of a IBM z Systems that is designed to provide users with attachments of up to 32 high-speed virtual LANs and is designed to minimize system and network overhead.

HiperSockets can be customized to accommodate varying traffic sizes. Because HiperSockets does not use an external network, it can free up system and network resources, helping to eliminate attachment costs while improving availability and performance.

HiperSockets eliminates the necessity of using I/O subsystem operations and traversing an external network connection to communicate between logical partitions in the same z Systems server. HiperSockets offers significant value in server consolidation by connecting many virtual servers, and can be used instead of certain coupling link configurations in a Parallel Sysplex environment.

HiperSockets internal networks on a IBM z Systems support two transport modes:

Traffic can be IPv4 or IPv6, or non-IP such as AppleTalk, DECnet, IPX, NetBIOS, or SNA.

For more information on the Open Systems Adapter features and HiperSockets, refer to the IBM z Systems Connectivity Handbook, SG24-5444, available at: Refer also to the OSA-Express Customer Guide and Reference, SA22-7935, available in the Publications section of Resource Link at:

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