Book C-87Chapter 2 Configuration ParametersRemote Annex Administrator’s Guide for UNIXBook Cppp_acmThis asynchronous port parameter (async control mask) specifies whichof the first 32 bytes (0x0 to 0x1F) of the ASCII character can be sent asclear text and which should be protocol-escaped.The Annex requests the ppp_acm parameter as its local mask. If the peerrejects ppp_acm, the Annex accepts the hint if it is a superset of theAnnex’s mask; otherwise, it uses the PPP default of 0xFFFFFFFF. TheAnnex accepts any mask from the peer. Values range from 0x00000000to 0xffffffff. The Annex default is 0x00000000.The ppp_acm parameter is a bit mask that is set as follows:• ppp_acm for ASCII NUL (decimal 0) is 2 to the power of 0 =0x00000001• ppp_acm for ASCII SOH (decimal 1) is 2 to the power of 1 =0x00000002• ppp_acm for ASCII DC1 (decimal 17) is 2 to the power of 17 =0x00020000• ppp_acm for ASCII DC3 (decimal 19) is 2 to the power of 19 =0x00080000Thus, the mask for XON/XOFF (DC1 and DC3) equals the OR functionof 0x00020000 and 0x00080000, or 0x000a0000.When the Annex sends an ACCM to the host, it follows this calculationto determine the initial value requested:• The value set for ppp_acm (a 32-bit integer) is read in as theACCM.
