IBM 890 manual Server to User connections, LPAR Support of OSA-Express, IPv6 Support

Note: OSA-Express 155 ATM and OSA-2 FDDI are no longer supported. If ATM or FDDI support are still required, a multiprotocol switch or router with the appropriate net- work interface for example, 1000BASE-T Ethernet, GbE LX or GbE SX can be used to provide connectivity between the LAN and the ATM network or FDDI LAN.

Server to User connections

A key strength of OSA-Express and associated Com- munications Server protocol support is the ability to accommodate the customer’s attachment requirements, spanning combinations of TCP/IP and SNA applications and devices. Customers can use TCP/IP connections from the remote site to either their TCP/IP or SNA applications on zSeries and S/390 by confi guring OSA-Express with QDIO and using either direct TCP/IP access or appropriate SNA to IP integration technologies, such as TN3270 Server and Enterprise Extender for access to SNA applications. Customers who require the use of native SNA-based con- nections from the remote site can use a TCP/IP or SNA transport to the data center and then connect into zSeries and S/390 using appropriate SNA support on OSA-Express features confi gured in non-QDIO mode.

LPAR Support of OSA-Express

For z890 customers or customers who use the Processor Resource/Systems Manager (PR/SM) capabilities of the z800, z900 and the S/390 servers, IBM offers the Multiple Image Facility (MIF), allowing the sharing of physical channels by any number of LPARs. Since a port on an OSA-Express fea- ture operates as a channel, sharing of an OSA-Express port is done using MIF. The LPARs are defined in the Hardware Confi guration Defi nition (HCD). Depending upon the feature, and how it is defi ned, SNA/APPN/HPR and TCP/IP traffi c can fl ow simultaneously through any given port.

IPv6 Support

IPv6 requires the use of an OSA-Express adapter running in QDIO mode and is supported only on OSA-Express features on zSeries at driver level 3G or above. IPv6 is supported on OSA-Express for zSeries Fast Ethernet, 1000BASE-T Ethernet and Gigabit Ethernet when running with Linux on zSeries, z/VM 5.1, and z/OS 1.4 and later.

Performance enhancements for virtual servers

Two important networking technology advancements are announced in z/VM 4.4 and Linux on z990.

•The high performance adapter interrupt handling fi rst introduced with HiperSockets is now available for OSA- Express/OSA-Express2 in QDIO mode (CHPID=OSD) and FICON Express/FICON Express2 (CHPID=FCP). This advancement provides a more effi cient technique for I/O interruptions designed to reduce path lengths and overhead in both the host operating system and in the adapter. This benefi ts OSA-Express TCP/IP support in both Linux for zSeries and z/VM.

•z990/z890 support of virtual machine technology has been enhanced to include a new performance assist for virtualization of adapter interruptions. This new z890/ z990 performance assist is available to V=V guests (pageable guests) that support QDIO on z/VM 4.4 and later. The deployment of adapter interruptions improves effi ciency and performance by reducing z/VM Control Program overhead.

OSA-Express2 large send for the z/OS environment –

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Previewing large send for TCP/IP traffi c

z/OS Communications Server plans to exploit OSA- Express2 large send (also referred to as TCP segmentation

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