ruck@sphere.UUCP (John R Ruckstuhl Jr) (05/25/90)
The recent discussion in sci.electronics regarding the accurate setting of clocks prompts this curiousness: How do long-distance telephone services maintain accuracy in time-stamping telephone connections? Precisely, how, and how often, are such clocks set, and what is their accuracy? I had no success in gleaning this information from customer service representatives at MCI and AT&T. I suppose this question is so unusual that they did not know the answer, nor know how to get the answer. Thank you, John. -- John R Ruckstuhl, Jr UUCP: sphere!ruck (or hplabs!hp-lsd!sphere!ruck) DOMAIN: ruck%sphere@hp-lsd.cos.hp.com
grege@gold.GVG.TEK.COM (Greg Ebert) (05/25/90)
In article <285@sphere.UUCP> ruck@sphere.UUCP (John R Ruckstuhl Jr) writes: > >How do long-distance telephone services maintain accuracy in >time-stamping telephone connections? Hey, those guys have a little racket going on: You are charged for every minute, or fraction thereof. So, if I make a call for 61 seconds, it will cost as much as one lasting 119 seconds.
arnief@tekgvs.LABS.TEK.COM (Arnie Frisch) (05/25/90)
In article <1021@gold.GVG.TEK.COM> grege@gold.GVG.TEK.COM (Greg Ebert) writes: >Hey, those guys have a little racket going on: You are charged for every >minute, or fraction thereof. So, if I make a call for 61 seconds, it will >cost as much as one lasting 119 seconds. What's worse is that some start charges about 30 seconds after you've completed dialing - IRRESPECTIVE OF WHETHER OR NOT YOUR CALL WAS COMPLETED! Arnold Frisch Tektronix Laboratories
thomas@mvac23.UUCP (Thomas Lapp) (05/26/90)
> >How do long-distance telephone services maintain accuracy in > >time-stamping telephone connections? > > Hey, those guys have a little racket going on: You are charged for every > minute, or fraction thereof. So, if I make a call for 61 seconds, it will > cost as much as one lasting 119 seconds. Right. So it makes a lot of sense for penny pinchers to watch the clock closely and make sure they get at least 45 of those 59 seconds used on that last minute ;-) - tom -- internet : mvac23!thomas@udel.edu or thomas%mvac23@udel.edu uucp : {ucbvax,mcvax,psuvax1,uunet}!udel!mvac23!thomas Europe Bitnet: THOMAS1@GRATHUN1 Location: Newark, DE, USA Quote : The only way to win thermonuclear war is not to play. -- The UUCP Mailer
ruck@sphere.UUCP (John R Ruckstuhl Jr) (05/27/90)
In article <7560@tekgvs.LABS.TEK.COM>, arnief@tekgvs.LABS.TEK.COM (Arnie Frisch) writes: > What's worse is that some start charges about 30 seconds after you've > completed dialing - > > IRRESPECTIVE OF WHETHER OR NOT YOUR CALL WAS COMPLETED! I've heard it alleged that MCI does this, so I asked an MCI customer service representative, who explained that has not been true for 10 years -- the switching equipment now in use allows them to begin charging when the call is answered. So I wonder (with no disrespect intended) whether this might be an urban myth based on obsolete information. Does anyone know a long-distance service which (still) does this? And, my original question, how does a telephone service provider maintain time-accuracy for billing, and how accurate is that time? -- John R Ruckstuhl, Jr UUCP: sphere!ruck (or hplabs!hp-lsd!sphere!ruck) DOMAIN: ruck%sphere@hp-lsd.cos.hp.com
thomas@mvac23.UUCP (Thomas Lapp) (05/28/90)
> So I wonder (with no disrespect intended) whether this might be an urban > myth based on obsolete information. Does anyone know a long-distance > service which (still) does this? I don't believe any of the long-distance services (of any size) do this. They all have equipment that recognizes when a call is answered (and if it is answered). Some smaller private systems, however, may still not have that capibility. This would be things like switches in hotels, or those places who route your calls over "their" system, and at "their" rates. As for the time question, you might want to ask the question in the telecom digest (comp.dcom.telecom?). That's where a lot of the telecom folks hang out. - tom -- internet : mvac23!thomas@udel.edu or thomas%mvac23@udel.edu uucp : {ucbvax,mcvax,psuvax1,uunet}!udel!mvac23!thomas Europe Bitnet: THOMAS1@GRATHUN1 Location: Newark, DE, USA Quote : The only way to win thermonuclear war is not to play. -- The UUCP Mailer
dean@pico.oz (Dean Economou) (05/29/90)
As far as I know, the telephone companies (RBOCs) use atomic clocks throughout their digital hierachy, and they are very careful not to overcharge. I'd guess that they use the same time reference for their billing too. Whether such care extends to the long haul carriers, I know not. Dean Economou [my opinions are independent of my employer's]
ruck@sphere.UUCP (John R Ruckstuhl Jr) (06/01/90)
In article <285@sphere.UUCP>, ruck@sphere.UUCP (John R Ruckstuhl Jr) writes: > How do long-distance telephone services maintain accuracy in > time-stamping telephone connections? > Precisely, how, and how often, are such clocks set, and what is their > accuracy? Someone writes me: why worry about time precision -- > I thought that billing changed with the time - if you make a phone call > at 4:58 that lasts for 10 minutes, you get the connect charge and the > first two minutes at the daytime rate, then the last 8 minutes at the > evening rate. For domestic long-distance telephone calls, AT&T and MCI adjust the billing rate (as described above). For international long-distance telephone calls, AT&T and MCI bill at the rate in effect when the call is placed. The time of connection would also important if the first minute of connection time is billed at a different rate than subsequent minutes. So I'm looking for assurance that when I place a telephone call at 17:00:30 I will be billed at the discounted rate, that a time-of-day error (I'm not concerned with elapsed-time) cannot occur on the long-distance provider's billing computer. Someone else writes or posts, very politely: this might belong in comp.dcom.telecom. Thank you -- I hadn't known that and hadn't recognized it from the description I had (not to say I shouldn't have recognized it): comp.dcom.telecom Telecommunications digest. (Moderated) But for now I continue what I've begun, here (until it dies, unresolved, and I'm forced to expand this host's limited feed to include that newsgroup (not to say that would be bad (smiley))). -- John R Ruckstuhl, Jr UUCP: sphere!ruck DOMAIN: ruck%sphere@hp-lsd.cos.hp.com
johne@hpvcfs1.HP.COM (John Eaton) (06/01/90)
<<<< < How do long-distance telephone services maintain accuracy in < time-stamping telephone connections? < Precisely, how, and how often, are such clocks set, and what is their < accuracy? ---------- I read a recent article about the Global Positioning System that said many surveyors and the telephone company count on its signals for time information. John Eaton !hpvcfs1!johne
rkarlqu@hpscdc.scd.hp.com (Rick Karlquist) (06/07/90)
All major phone systems have "Stratum 1" clocks employing Cesium Atomic clocks, which are typically accurate to a microsecond a day (for the cheap ones the phone companies buy). There are any number of fairly easy methods of resynching them to NIST time periodically. They need to have these clocks to generate accurate sync for the digital transmission schemes now in nearly universal use. (The signals are *not* self clocking and clock wander causes chucks of data to be lost). We happen to know that they also use these clocks for time-stamping purposes. Hence you don't have to worry about accurate time vis a vis billing when using a major phone company. Now these mickey mouse "alternate operator services" that own "private" pay phones I wouldn't trust at all, because they *want* to make errors (as long as they are in their favor!).