On Tue, Oct 03, 2006 at 08:44:16AM +0800, Steve Underwood wrote: > >>>So, y'know, that assertion gets made a lot. > >>> > >>>What's the turn rate of fax machines in the market? 3 years? 5? CNG > >>>tones are *well* over 10 years old, no? > >>> > >>What relevance does that have to CNG? It was a feature of the original > >>spec 30 years ago. > > > >Well, perhaps I wasn't paying attention, but I thought that CNG tones > >*had as their purpose* making receive FAX detection trivial. That > >would tend to make the question on-point, would it not? > > > It is the age of the machines which has no relevance.
Ah. My early memories of CNG tones suggested that early fax machines did not actually send them. > >My personal experience is that I've never seen a consumer-grade fax > >machine with send-CNG turned off, and I don't *think* I've ever seen > >one on which there was a knob *to* turn it off; I would be less sure > >about fax modems -- those may have a knob, but I would expect it to > >default on. > > > >Could you expand on what behaviour you think CNG breaks? Cause I'm not > >modeling it, mentally... > > I guess you touched many consumer grade fax machines, since *most* above > the very basic ones can do this in some way. Yeah, the only real "pro" grade fax machines I've ever run across was a Panafax I have that uses 3-inch core paper rolls, and I never really got that working. > Some have really fun behaviour. I used to suffer some Olivetti ones that > had several modes of calling and answering - Delay a while, to give > someone a chance to pick up first; Pick up, but remain silent and see > what the machine can hear; etc. Those Olivettis would only properly send > a fax to another Olivetti when they were in straight forward standard > mode. Now there's compatibility for you. :-) Yeah: "I'm so compatible with everyone else that I'm not compatible with myself" is kinda dumb. > A lot of other machines > offer similarly dumb modes of behaviour, but nothing quite so extreme as > those. When you investigate one of these issues, and ask the user why > the machine is not in simple answering mode, they are usually unaware it > is not. These modes get set largely at random on installed fax machines. Yay. > Now, it seems like these special modes should only affect answering. It > would seem they are mostly about doing what Asterisk is doing - waiting > silently for the 1100Hz tone. However, that's just too clean and simple > for the fax industry. They do a bunch of other dumb stuff to make things > more awkward, like call and only send something when they here 2100Hz. What fun. Cheers, -- jra -- Jay R. Ashworth [EMAIL PROTECTED] Designer Baylink RFC 2100 Ashworth & Associates The Things I Think '87 e24 St Petersburg FL USA http://baylink.pitas.com +1 727 647 1274 "That's women for you; you divorce them, and 10 years later, they stop having sex with you." -- Jennifer Crusie; _Fast_Women_ _______________________________________________ --Bandwidth and Colocation provided by Easynews.com -- asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
