Envoy ACP/XF Configuration and Management Manual

WAN Subsystem Profiles and Modifiers for
EnvoyACP/XF
EnvoyACP/XF Configuration and Management Manual—429232-003
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Optional Modifier Descriptions
You can set or override this modifier by issuing a SETMODE 19 call in an application
or by issuing an SCF ALTER LINE command to the EnvoyACP/XF subsystem.
FLAGFILL/NOFLAGFILL
Causes flag characters to be transmitted continuously between frames after a modem
connection has been established and the first frame has been sent. The use of this
modifier depends on the hardware configuration of the remote station. If the remote
station expects flags to be transmitted on an idle line, set the FLAGFILL modifier.
You can set or override this modifier by issuing a SETMODE 18 call in an application
or by issuing an SCF ALTER LINE command to the EnvoyACP/XF subsystem.
FRAMESIZE
Specifies the maximum size (in words) of read and write buffers for the line. Note that if
a FRAMESIZE value of greater than 2042 words is specified, internally EnvoyACP/XF
limits the value to 2042. FRAMESIZE includes the address and control fields of the
frame, but does not include the frame checksum. The appropriate value for
FRAMESIZE depends partly on the value of L2WINDOW, since L2WINDOW
determines the number of write frame buffers required for the line.
The default frame size (268 words) provides optimal performance for most line
conditions. On error-prone lines, larger frame sizes may degrade performance
because the large frames need to be retransmitted when errors occur.
You can set or override this modifier to a value less than the PROFILE value by
issuing a SETMODE 17 call in an application. You cannot use SETMODE to change
FRAMESIZE to a value greater than the PROFILE value. You can also issue an SCF
ALTER LINE command to the EnvoyACP/XF subsystem to change this modifier.
Default: NOFLAGFILL (Flag characters are not transmitted continuously.)
Units: N/A
Range: N/A
Default: 268 words
Units: Words
Range for dedicated bit-
synchronous
concentrators:
75 to 2042 (see note)
Note. FRAMESIZE must be less than the available total internal memory divided by
(L2WINDOW + 3).