Book C
ppp_acm
This asynchronous port parameter (async control mask) specifies which
of the first 32 bytes (0x0 to 0x1F) of the ASCII character can be sent as
clear text and which should be protocol-escaped.
The Annex requests the ppp_acm parameter as its local mask. If the peer
rejects ppp_acm, the Annex accepts the hint if it is a superset of the
Annex's mask; otherwise, it uses the PPP default of 0xFFFFFFFF. The
Annex accepts any mask from the peer. Values range from 0x00000000
to 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 =
0x00080000
Thus, the mask for XON/XOFF (DC1 and DC3) equals the OR function
of 0x00020000 and 0x00080000, or 0x000a0000.
When the Annex sends an ACCM to the host, it follows this calculation
to determine the initial value requested:
•
The value set for ppp_acm (a 32-bit integer) is read in as the
ACCM.
Remote Annex Administrator's Guide for UNIX
Chapter 2
Configuration Parameters
Book C-87