ACC HDLC-NRM (SDLC) User's Guide

SDLC Loop Mode Option
Introduction
Appendix B64
SDLC Frame Types Not Supported
The following commands and responses defined in the IBM SDLC
specification are not supported:
Modulo-128 sequence numbering is also not supported.
Commands Responses
CFGR BCN
XID CFGR
REJ RD
XID
REJ