larry@uunet.uu.net> (04/06/90)
In article <3759@accuvax.nwu.edu> dave%westmark@uunet.uu.net (Dave Levenson) writes: > You can make a line busy by taking it off-hook. The telco will send > you ROH tone, and may get annoyed if you do it a lot, however. If > you use a switch that connects a resistor of about 600 ohms between > Tip and Ring, it probably won't affect a call in progress (may drop > the audio level a bit). When the call ends, the line will appear to > remain off-hook, and the CO will just hunt around it. If you are implying that the above technique will NOT result in a CO permanent signal (i.e., ROH), but that the line will still be marked busy, then you are incorrect. Almost all CO apparatus (except perhaps some ancient SxS, XY, North CX or Leich) today has timed disconnect on connectors (SxS and XY) and intra and interoffice trunks (anything else). If you are the callING party, when the callED party answers and then eventually disconnects, and if you remain on the line (which the 600 ohm resistor will accomplish) timing (typically 20 to 30 seconds) starts to release the switch train or intraoffice or interoffice trunk - you then get dumped back to dial tone. If you are the callED party and you fail to disconnect after the callING party disconnects, you will be immediately disconnected and dumped to dial tone. There is, in general, no way to make busy a CO line without creating a permanent signal in the CO. Most telephone companies have a tariff for a make busy arrangement to avoid this problem, but you don't even want to think about the cost of this service since it requires a dedicated pair from the CO for a make-busy key. Incidently, newer ESS CO's even have a feature which disconnects a callING party after a proscribed time (usually 3 minutes) if a callED party does NOT answer. <> Larry Lippman @ Recognition Research Corp. - Uniquex Corp. - Viatran Corp. <> UUCP {boulder|decvax|rutgers|watmath}!acsu.buffalo.edu!kitty!larry <> TEL 716/688-1231 || 716/773-1700 {utzoo|uunet}!/ \uniquex!larry <> FAX 716/741-9635 || 716/773-2488