User guide

240 RealCT Direct API Developer Guide
Appendix B: E1 Line Protocols
R2-CCITT - Central European Implementation
The Central European implementation of the R2-CCITT
protocol uses the same timing and bit patterns as the R2-CCITT
but with a different disconnect procedure, as shown in Table 44.
Table 44. R2-CCITT Central European: CO Calls CPE
(*) Incoming end initiating disconnect.
(**) Outgoing end initiating disconnect.
Status CO CPE
Idle 10 10
Seizure 00 --> 10
Acknowledgment 00 <-- 11
R2 Inter-register
Signaling
00 11
Answer 00 <-- 01/11/01
Conversation 00 01
Clear Back 00 <-- 11
Clear Forward * 10 --> 11
Clear Forward 10 --> 01
Release Guard 10 <-- 11
Release ** 10 <-- 10
Blocked 10 11
Hook Flash 00 <-- 01/11/01
00/10/00 --> 01