z/OS connectivity
z/OS®requires channel based network devices (OSD devices provided by an OSA Express adapter or OSH devices provided by a Network Express adapter in hybrid mode) for TCP/IP connections to an external LAN.
z/OS can use PCI functions for RDMA traffic as used by SMC-R connections.
For TCP/IP connections, which initialize SMC-R connections, z/OS needs an OSH device or OSA-Express adapter to establish SMC-R connections through PCI network adapters. With Network Express®, both OSH and NETH can be provided by the same Network Express adapter in hybrid mode.
At the Linux® end of a TCP/IP connection, you can use an OSA-Express adapter or a PCI network adapter. You can connect a PCI network adapter from Linux to an OSA-Express adapter at the z/OS end of the connection through a LAN switch, a router, or even through direct cabling.