IBM has announced that they will withdraw native support to the SNA and Legacy Protocol adapters such as X.25, this since version 7.4 of IBM i® Operative System.
In the document published via IBM Knowledge Center, IBM points the withdrawal of SNA native adapters, affecting configurations like SNA FAX, Finance, Retail, and Remote Workstation, whereby IBM deletes support to DDI, Token-Ring, Wireless, Frame Relay, SDLC, TDLC, and X.25 protocols.
Along with IBM’s announcement, CLAI Payments® will withdraw of its payment platform AZ7® in its 5.0 version any functionality related to these protocols and controllers.
Source: https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_74/rzaq9/rzaq9.pdf?view=kc