| | | | | | | | | | | | | | |
|
|
| Interface
Codes
|
| 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 signaling bits
|
|
|
|
|
|
|
| DI3
|
| Digital Interface containing encode analogue
|
|
|
|
|
|
|
| DSC
|
| Digital Subrate Channels
|
|
|
|
|
|
|
| GS
|
| Ground Start
|
|
|
|
|
|
|
| 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
|
|
Certification and Engineering Bureau
