Toshiba DK424I Telephone User Manual


 
ISDN
Call-By-Call Overview
7-12 Strata DK Programming 5/00
Call-by-Call Min/Max Control
There are two variables that can be programmed for each trunk group to ensure optimum call
utilization. These are the minimum and maximum values.
The minimum (min.) value is defined as the minimum number of B-channels in reserve that
are necessary to ensure that a given trunk group can adequately service calls. The default value
is zero.
The maximum (max.) value is the maximum number of B-channels that are necessary to
ensure that a given trunk group can adequately service calls during a peak period. The default
value is 23.
The min and max values must be determined by you based on the traffic volume and environment.
Here are some guidelines:
The total number of lines assigned to all trunk groups as minimums should not exceed the
number of B-channels in the channel group. For example, if there are 23 B-channels in the
channel group, the total sum value programmed as minimum in all trunk groups should not
exceed 23.
The maximum value typically never exceeds the total of the subscribed B-channels for the
channel group. The programmed maximum value is typically used to limit the total number of
shared lines available to a given trunk group.
Example 2
This example shows how to determine the maximum number available to a trunk group.
Refer to Figure 7-3. Add the min. values from the other trunk groups, then subtract that sum from
the number of B channels in the channel group. The remainder is the total number of lines
available for that trunk group. This is outlined in steps 1 and 2 below.
Maximum trunk group values are set in Program
*
67-4. Minimum trunk group values (reserved)
are set in Program
*
67-3.
Channel Group 1
Max. = 23
Min. = 8
Trunk Group 1
Max. = 12
Min. = 5
Trunk Group 3
Max. = 7
Min. = 3
Trunk Group 2
4917
1. Determine the total number of lines
available to Trunk Group 1.
2. Subtract from other Trunk Groups
min. values from the number of
B-channels in that Channel Group.
3
Trunk Group 2 Min.
+ 5
Trunk Group 3 Min.
8
Min. Value for Trunk Groups 2 & 3
23
B-channels in Channel Group 1
- 8
Min. Value for Trunk Groups 2 & 3
15
Lines available to Trunk Group 1
(8 reserved + 7 shared)
Note Even through the max. value is
set for 23 channels, only 15
channels are available for
Trunk Group 1.
Figure 7-3 Example 2 Shared Trunk Lines