AT&T System 25 - Manual (Page 348)

APPENDIX E: Administration Codes and Data
Table E-O. Trunk Class-of-Service (for all trunks except DID)
TRUNK CLASS-OF-SERVICE
(FOR ALL TRUNKS EXCEPT DID)
C O S NIGHT OUTWARD I N SHORT
CODE SERVICE SIGNALING ONLY DISCONNECT
0 TT
1 TT
●
2 TT
●
3 TT
● ●
4 DP
5 D P
●
6 DP
●
7 DP
● ●
8 ●
TT
9 ●
TT
●
10
●
TT ●
11
●
TT
● ●
12
●
DP
13 ●
DP
●
14 ●
DP
●
15
●
DP
● ●
TT=Touch-Tone
DP=Dial-Pulse
E-29