Filter
Top Products
General Information
November 2009 268
Timer Definitions
The LEC structure (named IISDN_ROBBED_BIT_DATA for
historical reasons) contains a series of 16-bit values used to configure
the various timing parameters associated with the protocols.
Table 13 lists the timers in alphabetical order and contains each
timer's unit, meaning, and default value. The unit indicates by how
much a timer value must be multiplied to find its actual duration in
milliseconds, while the default (the number in parentheses following
its define value) indicates the number of ticks.
Proper timing with LEC protocols is very important. There are over
30 unique timings that are set, with a significant subset of these
applicable to several protocols. You should match their entries in the
table to the appropriate timing diagrams.
Table 13. Robbed Bit Signaling Timers
Timer Granularity Definition Default Value
answer_timer 50 ms Timed Answer Supervision.
Timer started after the last digit
has been dialed. Used to report
distant end answer when the
protocol doesn't provide a
specific signal to indicate the
called party has answered the
call.
IISDN56_ANSW_TIMER_
DEFAULT (60)
3 seconds
critical_timer 50 ms Critical Interdigit Timer. While
racking incoming distant digits,
the maximum time to wait
between digits before giving up
and returning an incomplete
rack.
IISDN56_CRIT_TIMER_
DEFAULT (20)
1 second