IBM 890 manual HiperSockets

HiperSockets

offl oad). Large send can improve performance by offl oad- ing outbound TCP segmentation processing from the host to OSA-Express2 by employing a more effi cient memory transfer into OSA-Express2. The z/OS Communications Server support is planned for TCP/IP IPv4 traffi c only and z/OS and z/OS.e 1.7. In addition, a z/OS and z/OS.e 1.6 PTF is planned to be provided.

Large send support applies to the OSA-Express2 features (Gigabit Ethernet SX and LX, 10 Gigabit Ethernet LR), sup- ports QDIO mode only (CHPID type OSD), and is exclu- sive to z990 and z890. Large send support was previously announced for the Linux on zSeries environment.

HiperSockets, a feature unique to the zSeries, provides a “TCP/IP network in the server” that allows high-speed any- to-any connectivity among virtual servers (TCP/IP images) and LPARs within a zSeries system without any physical cabling. HiperSockets decreases network latency and increases bandwidth between combinations of Linux, z/OS and z/VM virtual servers. These OS images can be fi rst level (directly under an LPAR), or second level images (virtual servers under z/VM).

With new support for up to 16 HiperSockets, the z890 and z990 provides four times more HiperSockets, and up to 4,096 TCP/IP images (stack) connections, which is also four times more capacity than the z800 and z900. The increased HiperSockets capacity and expanded con- nectivity provides additional fl exibility in designing the networking to accommodate consolidated and multiple partitioned systems. HiperSockets can be divided among Logical Channel SubSystems for separation between vari- ous LPARs, while at the same time a single LPAR could have access to all 16 HiperSockets if the HiperSockets all are assigned to the same LCSS.

A HiperSockets channel also supports spanned channels in order to communicate between LPARs connected to different LCSSs. HiperSockets (IQD CHPID type) can be confi gured to Channel SubSystems and transparently shared by any or all confi gured LPARs without regard to the LCSS to which the LPAR is confi gured. This means one HiperSockets could be common to all 30 z890 or

z990 LPARs. This support is exclusive to z890 and z990. Different HiperSockets can be used for security (separa- tion of traffi c, no external wire-tapping, monitoring) and performance and management reasons (separate sysplex traffi c Linux or non-sysplex LPAR traffi c).

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