Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uakari.primate.wisc.edu!sdd.hp.com!wuarchive!julius.cs.uiuc.edu!apple!bionet!hayes.ims.alaska.edu!accuvax.nwu.edu!nucsrl!telecom-request From: IZZYAS1@oac.ucla.edu (Andy Jacobson) Newsgroups: comp.dcom.telecom Subject: Re: Dialing Own Number Brings a Surprise Message-ID: <15131@accuvax.nwu.edu> Date: 1 Dec 90 09:41:00 GMT Sender: news@accuvax.nwu.edu Organization: TELECOM Digest Lines: 42 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 858, Message 12 of 13 I should note that from the GTD-5 and 2EAX switches here in GTE-land, just dialing your own number is how you get ringback. (See TELECOM Digest Guide to Special Prefixes/Numbers.) In TELECOM Digest, V10 #855, John Higdon writes: >Pac*Bell Weenie Note: In the Pac*Bell implementations of the 1AESS >(W.E. should never have provided them with the source!), you would >still get busy, even when dialing through Telecom*USA. PB's generic >will not allow CW or 3W until the first call is supervised. Pac*Bell >had some lame reason for doing this, but I forgot what it was. With 3W, I assume Pac*Bell does this to prevent you from invoking the second dial tone if you're trying to hang up (with no answer), and dial again . GTE's 1E software thankfully does this too at least within the same CO. (I say thankfully, as it seems you have to go on hook for an eternity of 3 or 4 seconds to get rid of the first call before getting fresh dial tone.) Another reason I can see for Pac*Bell's implementation would be so that you don't switch to the second call before the first called party answers, to dead air. This would also prevent you from crank connecting two calls to each other before they answer. (This sort of "mix and match"ing is probably a major crank caller fantasy.) With CW, dead air also applies. Might there also be some detection problem if you come back from CW (switchhook flash) at the same instant that the first called party answers (DC reversal or voltage drop as supervision begins)? With CW looped outside the local switch, GTE differs. If I call number A (GTD-5 switch) from number B (1AESS) that number A is forwarded to, I get CW beep before I hear distant ringing. I can flash to put the orig segment on hold and answer the loop around, and flash back and forth to my heart's content (always with one segment or the other on hold). Supervision would appear to play no part in it. However, when I hang up on either segment, it does not ring me to tell me that there is a call on hold. Though logically, if I hang up on the loop around segment it should This gets to be rather abstract stuff after a while. Andy Jacobson