Shared Memory Communications D This appendix briefly describes the optional Shared Memory Communications (SMC) function  that is implemented on IBM Z servers as Shared Memory Communications over Remote  Direct Memory Access (SMC-R) and Shared Memory Communications - Direct Memory  Access (SMC-D) of IBM z14, z13, and z13s servers.  Note:  Throughout this chapter, “z14” refers to  IBM z14 Model M0x (Machine Type 3906)  unless otherwise specified. This appendix includes the following topics: GLYPH<SM590000> D.1, “Overview” on page 476 GLYPH<SM590000> D.2, “Shared Memory Communication over RDMA” on page 476 GLYPH<SM590000> D.3, “Shared Memory Communications - Direct Memory Access” on page 489 475 ' Copyright IBM Corp. 2017. All rights reserved.