The maximum supported unrepeated distance, point-to-point, is 300 meters (984 ft). A  client-supplied cable is required. The following types of cables can be used for connecting the  port to the selected 10 GbE switch or to the 10GbE RoCE Express feature on the attached  server: For more information about the management and definition of the 10GbE RoCE, see  Appendix D, “Shared Memory Communications” on page 475, and Appendix C, “Native  Peripheral Component Interconnect Express” on page 469. The Shared Memory Communication (SMC) capabilities of the z14 help optimize the  communications between applications for server-to-server (SMC-R) or LPAR-to-LPAR  (SMC-D) connectivity. SMC-R provides application transparent use of the RoCE-Express feature. This feature  reduces the network overhead and latency of data transfers, which effectively offers the  benefits of optimized network performance across processors.  SMC-D was used with the introduction of the Internal Shared Memory (ISM) virtual PCI  function. ISM is a virtual PCI network adapter that enables direct access to shared virtual  memory providing a highly optimized network interconnect for IBM Z intra-CPC  communications.  SMC-D maintains the socket-API transparency aspect of SMC-R so that applications that use  TCP/IP communications can benefit immediately without requiring any application software or  IP topology changes. SMC-D completes the overall SMC solution, which provides synergy  with SMC-R. SMC-R and SMC-D use shared memory architectural concepts, which eliminates the TCP/IP  processing in the data path, yet preserves TCP/IP Qualities of Service for connection  management purposes.  ISM is a function that is supported by IBM z14™, z13, and z13s machines. It is the firmware  that provides connectivity by using shared memory access between multiple operating  system images within the same CPC. ISM creates virtual adapters with shared memory that  is allocated for each OS image.  Shared Memory Communications functions Internal Shared Memory GLYPH<SM590000> OM3 50-micron multimode fiber optic cable that is rated at 2000 MHz-km that ends with an  LC Duplex connector (supports 300 meters (984 ft)) GLYPH<SM590000> OM2 50-micron multimode fiber optic cable that is rated at 500 MHz-km that ends with an  LC Duplex connector (supports 82 meters (269 ft)) GLYPH<SM590000> OM1 62.5-micron multimode fiber optic cable that is rated at 200 MHz-km that ends with  an LC Duplex connector (supports 33 meters (108 ft)) 182  IBM z14 (3906) Technical Guide ISM is defined by the FUNCTION statement with a virtual CHPID (VCHID) in hardware  configuration definition (HCD)/IOCDS. Identified by the PNETID parameter, each ISM VCHID  defines an isolated, internal virtual network for SMC-D communication, without any hardware  component required. Virtual adapters are defined by virtual function (VF) statements. Multiple  LPARs can access the same virtual network for SMC-D data exchange by associating their  VF with same VCHID.  Applications that use HiperSockets can have network latency and CPU reduction benefits and  performance improvement by using the SMC-D over ISM.