>Date: 22 Jan 97 11:12:49 EST >From: David Drori <[email protected]> > >1. A message-waiting indication facility is commonly available for PBXs, and >is intended for the hotel/motel market. The systems that I have encountered >use a neon lamp mounted in each guest's telephone set, which is illuminated >by a higher than normal telephone line voltage -- 150 volts or so -- when >the guest has messages waiting.
>Assuming that a voice mail service is provided by US telephone companies (is >this assumption correct?) on CO lines, is a message-waiting lamp feature >available, and if so, does it use the high DC voltage arrangement of the kind >described above? A PBX message waiting feature typically uses 100 VDC pulses to make a neon bulb glow in a special telephone. This feature cannot be used on a normal telephone, because a neon bulb message waiting device in a telephone causes it to fail the "DC On-hook" requirements of FCC Part 68 and CS-03. >3. If, indeed, caller ID is used to indicate that messages are waiting, which >Standard specifies the protocol used for transmitting this specific >information? I believe that U.S./Canadian telcos all use the same Bellcore standard for this feature now, which is described in "Visual Message Waiting Indicator Generic Requirements," TR-NWT-001401, Issue 1, September 1993, which is a Module in the Bellcore LSSGR series, FR-NWT-000064. Briefly, this is a CLASS message, and there are some additional details about it in Bellcore SR-3004, Issue 2, Section 3.2.6. ________________________________________________________________ John Combs, Senior Project Engineer, ITS/TestMark Laboratories Email: [email protected] URL: http://www.testmark.com
