8860ch02.fm Draft Document for Review September 23, 2019 1:36 am control layer of an OSA-Express QDIO interface, and uses no physical cabling or external  networking connections. Data access is performed at memory speeds, bypassing external  network delays and providing the users with high-speed logical LANs with minimal system  and network overhead. HiperSockets can be defined as Multiple Image Facility (MIF)-shared in a CSS and as  spanned channels across multiple CSSs. A HiperSockets CHPID can be seen as an  internal  LAN  to the server. The level of sharing is determined by the logical partitions you want to  grant access to that LAN. HiperSockets is supported by the following operating systems: On a z15, HiperSockets support the following functions:  Supported across HiperSockets on Internet Protocol Version 4 (IPv4) for applications.  Applications that use the broadcast function can propagate the broadcast frames to all  TCP/IP applications that are using HiperSockets. This support is applicable in Linux, z/OS,  and z/VM environments. Virtual local area networks (VLANs) are supported by Linux on z Systems and z/OS V1R8  or later for HiperSockets. VLANs can reduce overhead by allowing networks to be  organized by traffic patterns rather than physical location. This enhancement allows traffic  flow on a VLAN connection both over HiperSockets and between HiperSockets and  OSA-Express Ethernet features. Traffic between HiperSockets and OSA-Express can be transparently bridged by using the  HiperSockets Network Concentrator. This configuration eliminates intervening network  routing overhead, resulting in increasing performance and a simplified network  configuration. This improvement is achieved by configuring a connector Linux system that  has HiperSockets and OSA-Express connections defined to it. HiperSockets supports two transport modes on the z15 Layer 2 (Link Layer) and Layer 3  (Network and IP Layer). As with Layer 3 functions, HiperSockets Layer 2 devices can be configured as primary or  secondary connectors or multicast routers. These configurations enable high performance  and highly available Link Layer switches between the HiperSockets network and an  external Ethernet. HiperSockets performance has been increased by allowing streaming of bulk data over a  HiperSockets link between logical partitions. Multiple writes with fewer I/O interrupts  reduce processor usage of both the sending and receiving logical partitions, and is  supported in z/OS GLYPH<SM590000> HiperSockets Completion Queue GLYPH<SM590000> HiperSockets multiple write facility GLYPH<SM590000> HiperSockets Layer 2 support GLYPH<SM590000> HiperSockets Network Concentrator GLYPH<SM590000> IPv6 support on HiperSockets GLYPH<SM590000> VLAN support  GLYPH<SM590000> HiperSockets Broadcast  GLYPH<SM590000> All in-service z/OS releases GLYPH<SM590000> All in-service z/VM releases GLYPH<SM590000> All in service z/VSE releases GLYPH<SM590000> Linux on Z Chapter 2. Planning considerations for CPC in PR/SM mode  27