Path: utzoo!attcan!uunet!mailrus!accuvax.nwu.edu!nucsrl!telecom-request From: john@bovine.ati.com (John Higdon) Newsgroups: comp.dcom.telecom Subject: Re: Loop Start vs Ground Start, a User Intro Message-ID: <6320@accuvax.nwu.edu> Date: 12 Apr 90 08:07:12 GMT Sender: news@accuvax.nwu.edu Reply-To: John Higdon Organization: TELECOM Digest Lines: 45 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 250, Message 2 of 11 Todd Inch writes: > Whats the difference in the phone sets for ground start vs loop start? > (Does anyone even make a ground-start phone, or do they always get > "converted" to loop by the PBX's?) Except for some lineman's sets, there are no "ground-start phones". Ground-start trunks are for PBXs and other complex equipment, not for ordinary telephone sets. > For example, how would you use a butt set to connect and place a call > on a loop start line? Do you need an earth-ground connection, or > temporary earth-ground connection? Yes, it's as simple as that. You put a phone across the line in an "off-hook" condition, then momentarily apply ring ground until dial tone is seized. > If you were to build a ground-start phone, would it need three wires? Yes, but why bother? > Also, are ground-start lines available from all CO's? Are they the > same cost (typically) as a "business" POTS/loop-start line? Ground-start lines and trunks are generally available in the US. In California, it matters not whether you order ground-start or loop-start. There is no difference in cost. If you wanted ground-start on your home phone it would be no problem. The difference in cost (other than the difference between res. and bus. service) comes from whether you want "design" circuits or not. Start type is not the factor. There is a significant charge to change from one to the other on an existing line, however. > Are ground-start lines ever used for residential service? Were the > grounds required on old phones just for the ringer? Ground-start has nothing to do with the ringer. I have had friends who had ground start lines in their homes, but it was primarily for toy value, or to service their prized vintage PBX. John Higdon | P. O. Box 7648 | +1 408 723 1395 john@bovine.ati.com | San Jose, CA 95150 | M o o !