# EUC signaling for Italy (Norma CEI 103-1\7)

The following table shows signaling states associated with the EUC TCP for Italy:

State | Outbound AfBf | Direction | Inbound AbBb
--- | --- | --- | ---
Idle | 01 |  | 01
Seizure | 10 |  | 01
Seizure acknowledged | 10 |  | 11
The outbound side starts to send the address information using DTMF tones or decadic pulses. If the method is decadic pulses, the Af bit is switched off (pulse on) and on (pulse off) repeatedly to signal the digits.
Register signaling: digit spill | DTMF |  | 11
Register signaling: pulse dial | 00 pulse on |  | 11
| 10 pulse off |  | 11
All the address information has been transferred. Now the inbound side must accept or reject the call by sending a wink: a temporary change in the bit pattern. The bit pattern is AB=10 if the inbound accepts the call, AB=01 if it rejects the call.
End of selection - free | 10 |  | 11-10-11 (150 ms)
End of selection - busy | 10 |  | 11-01-11 (150 ms)
If the call is accepted, the inbound side plays a ring tone on the line after resuming to signal AB = 11 (seizure acknowledged). If the call is rejected, the outbound side switches back to signaling AB = 01 (idle), clearing the line.
Ringing | 10 |  | 11
Answer - conversation state | 10 |  | 00
The outbound protocol can receive billing pulses to signal that a unit of cost has been billed to the call. In this case, the answer pattern (AB = 00) from inbound temporarily changes to AB = 10. Billing pulses are generated by the network, not by the inbound terminal.
Billing pulses | 10 |  | 00-10-00 (125 ms)
Depending on which side hangs up the call first, a clear back signal or a clear forward signal is generated. A period of release guard from inbound follows both signals, meaning acknowledgment of the clear operation. Idle follows.
Inbound hangs up first: Clear back | 10 |  | 01
Clear forward | 01 |  | 01
Release guard | 01 |  | 11
Idle | 01 |  | 01
Outbound hangs up first: Clear forward | 01 |  | 00
Release guard | 01 |  | 11
Idle | 01 |  | 01