Dialogic 6.2 manual 921/Q.931 Timers, Timers Level 2 Parameters Data Type Mnemonic Definition

Q.921/Q.931 Timers

Q.921/Q.931 Timers

An application can change the default behavior in Instant ISDN Software Level 2 and Level 3 parameters by issuing ENABLE_

PROTOCOL.

L4L3mENABLE_PROTOCOL contains an IISDN_L2_CONST structure that defines Level 2 parameters and an IISDN_Q931_ TIMERS structure that configure Level 3 timers. The IISDN_Q931_ TIMERS structure is only valid when the Level 3 mode (l3_mode) value in the message is IISDNl3modQ931. Table 15 and Table 16 list the parameters for both structures.

When altering these values, refer to the system specification for the switching system to which you are connecting the Brooktrout Controller for valid timer and window values. Level 2 timers are specified in 1 millisecond “ticks;” Level 3 timers in 100 millisecond “ticks.”

Note: Dialogic strongly recommends that you use the default values for Level 2 and Level 3 parameters and internal buffers. Failure to do so might result in a system irregularity. If you do need to change the configurations and buffer sizes, call Dialogic Technical Services and Support first and seek consultation. Internal buffer sizes for different Brooktrout Controller configurations are found in IISDN.h.

Table 15. Q.921 Timers (Level 2 Parameters)

Data Type	Mnemonic	Definition
IISDN_L2_	12	Setting a field to 0 causes the default value to be
LAP_		used. Some timers have two possible default values
CONSTS		depending on whether or not the line is a BRI (set
		by the q931_cnfg.basic_rate flag.
unsigned	t200	Maximum retransmission time. Default value is
short		1000 (1 second).
unsigned	t201	Minimum retransmission TEI Identity check.
short		Default value is 1000 (1 second).
unsigned	t202	Minimum TEI Identity request. Default value is
short		2000 (2 seconds).
unsigned	t203	Maximum link inactivity. Default value is 30
short		seconds. For NET-5 signaling, this timer should be
		set to 10 seconds. BRI default is 10000 (10
		seconds).

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