Hi George,

1) The physical layer caller ID specifications in different regions differ even though all provide caller ID information. Please consult current caller ID documents when implementing a system.

2) North American caller ID services were defined by Bellcore. The documents GR-30-CORE and SR-TSV-002476 specify the CO/CPE interface for caller ID and CIDCW.

3) Two bodies that have produced Caller ID specifications for the U.K. are British Telecom (BT) and the Cable Communications Association (CCA). BT’s specifications are contained in Suppliers Information Notes SIN227 and SIN242. The CCA document is TW/P&E/312 as an alternative for British Telecom.

Unlike North American caller ID in which the information is transmitted between the first and second rings, BT specifies that CID information should be transmitted before the first ring. 1200 baud CCITT V.23 FSK format is used.

The additional information on Custom Local Area Service you can obtain from BELLCORE CUSTOMER SVS
1–800–521–2673
201–699–5800 FOREIGN CALLS
201–699–0936 FAX
The document number is: TA–NWT–000030
Title: "Voice Band Data Transmission Interface Generic Requirements"

Hope it helps you a little.

Bye now,
George