HiperSockets
offl oad). Large send can improve performance by offl oad- ing outbound TCP segmentation processing from the host to
Large send support applies to the
HiperSockets, a feature unique to the zSeries, provides a “TCP/IP network in the server” that allows
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
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