Panasonic CPC-EX User Manual

Section 300-Installation

Chapter 4. Trunks and Lines

DBS-2.3/9.2-300

DBS Manual - Revised April 2000

  4-13

• Fractional T1 can be used when fewer than 24 T1 trunks are needed. 

Fractional T1 allows you to use only a portion of the 24 channels provided 
on the T1 card.

• Though each T1 Interface provides 24 trunk channels, T1 trunks do not 

increase the overall trunk capacity of the DBS. Each T1 channel subtracts 
from the total number of analog trunks that can be installed. 

• With CPC-B earlier than 5.00, the number of analog trunks that can be 

used with Fractional T1 are always decremented in quantities of 8. 

For example, if you are installing a T1 in a DBS 96 and you only want to 
use 12 T1 channels, the logical number of analog trunks that would be 
available is 20 (32 - 12 = 20).

The number of analog trunks must be decremented in quantities of 8, the 
actual number of analog trunks that can be used is 16:

(32 total trunks - 16 (two 8-trunk increments) = 16.)

Tables 4-9 through 4-11 show the possible combinations of analog and 
digital trunks assignments based on system size.

The trunk numbering shown in these tables is determined by backplane 
trunk port assignments. Therefore, the numbering cannot be changed.

• With CPC-B 5.00 and higher and the VB-43511A Loop Start Trunk Card, 

the number of analog trunks that can be used with Fractional T1 are 
decremented in quantities of 1.  

Note: Analog trunks are numbered beginning with “1.” T1 trunk channels 
are numbered beginning with the highest trunk channel used.

DBS 40 + DBS 40

No

Yes

DBS 72 + DBS 40

No

No

DBS 72 + DBS 72

No

Yes

DBS 96 + DBS 40

Yes

Yes

DBS 96 + DBS 72

Yes

Yes

DBS 96 + DBS 96

Yes

Yes