Network interfaces Code | Description |
A1 | Type A Tie Trunk type I signalling |
A2 | Type A Tie Trunk type II signalling |
B1 | Type B Tie Trunk type II signalling |
B2 | Type B Tie Trunk type II signalling |
CT | Type C Tie Trunk |
DI1 | Digital Interface |
DI2 | Digital Interface with signalling bits |
DI3 | Digital Interface containing encode analogue |
DSC | Digital Subrate Channels |
GS | Ground Start |
HEI | Handset with CS-03 Exempted Interface (HAC / ROLR) |
IST | ISDN S/T Reference |
ISTA | ISDN S/T reference with encoded analogue |
IUB | ISDN U reference Basic Rate Access |
IUP | ISDN U reference Primary Rate Access |
LS | Loop Start |
MC | Metallic Channels |
OPP | Off Premises Station Proprietary |
OPS | Off Premises Station |
PL | Private Line (lease line) |
RB | Reverse Battery |
RL | Release Link Trunk |
WH | Wireless Handset only (HAC / ROLR) |