Page96 of 544 Provisioning
553-3011-100 Standard14.00 January 2002
This method is used for each trunk group in the system, with the exception of
small special services trunk groups (such as tie, WATS, and FX trunks).
Normally, the customer will tolerate a lesser grade of service on these trunk
groups. Table20 lists the estimated usage on special services trunks.
Default method
Studies conducted estimate that the average line CCS/T is never greater than
5.5 in 90 percent of all businesses. If attempts to calculate the CCS/T using
the comparative method or the manual calculation are not successful, the
default of 5.5 line CCS/T can be used.
The network line usage is determined by multiplying the number of lines by
5.5 CCS/T. The total is then multiplied by two to incorporate the trunk CCS/
T. However, when this method is used, the intra CCS/T is added twice to the
equation, and the result could be over provisioning if the intra CCS/T is high.
Another difficulty experienced with this method is the inability to forecast
individual trunk groups. The trunk and intra CCS/T are forecast as a sum
group total. Examples of the default method and the manual calculation
method are shown in Table21 for comparison.
Table 2 0
Estimated load per trunk
Trunk type CCS
Tie 30
Foreign exchange 30
Out WATS 30
In WATS 30
Paging 10
Dial dictation 10
Individual bus lines 20