POTS line quality help
in [Design]
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From: Martin Brown on 30 Apr 2010 03:59 Michael A. Terrell wrote: > Martin Brown wrote: >> Michael A. Terrell wrote: >>> started disappearing over 25 years ago in the US. My first encounter was >>> when the phone company ripped out a leased pair between a fire station & >>> their siren at a paper mill a half mile away. That caused a mad >> If you had a leased line from the telco then they have to provide a >> functionally equivalent replacement service over a virtual circuit. What >> you say does not make sense. > > It's simple. They were using it as a simple low voltage, current > limited remote switch which wasn't guaranteed by the contract, but the Then the phone company was entirely within their rights to snip it. > phone company knew it was there and let them get away with it for > decades. Prior to that the dispatcher had to call the factory to have > the siren activated by an employee. A leased line was still available, > but was no longer a direct copper path between the two buildings. > Technology moves on, and old equipment is retired as it happens. Since > a lot of small departments had to move to radio control, the county set > up a county wide control system so they could set off the siren > directly. the could chose a single station, a small group, or in a > disaster, every station in the county. > >> I don't see what the problem is. The end >> user never knows what the details of the local exchange technology is. >> >> Or are you saying that some cowboys from the fire service way back when >> piggybacked a siren connection into telco circuit trunking and telco >> snipped the cables when the upgraded to fibre optics? > > Fiber to the premise in the '80s? Dream on! That seemed to be what you were claiming. We had internal fibre links on campus as a part of one of the earliest WANs in the early 1980's. >>> scramble to convert it (and others) to remote control by VHF radio. >>> That took over $1000 out of the volunteer fire department's budget. >> Why could you not continue with telco leased line service? > > It was no longer compatible with a simple SPST wall mounted switch > across the line. So you were using a spurious feature that was not supported by the telco. Pretty much as I suspected a prehistoric jerry rigged cowboy wiring solution that they did not guarantee to support. Regards, Martin Brown
From: Robert Baer on 30 Apr 2010 15:28 JosephKK wrote: > On Wed, 28 Apr 2010 16:45:04 -0700, Robert Baer <robertbaer(a)localnet.com> > wrote: > >> Robert Baer wrote: >>> JosephKK wrote: >>>> On Tue, 27 Apr 2010 11:39:06 -0700, Robert Baer <robertbaer(a)localnet.com> >>>> wrote: >>>> >>>>> Martin Brown wrote: >>>>>> Robert Baer wrote: >>>>>>> Martin Brown wrote: >>>>>>>> denali wrote: >>>>>>>>> FYI, RE: JB's post.. leased line parameters are in no way applicable >>>>>>>>> to switched services. Forget about 3002 channels, etc. >>>>>>>>> >>>>>>>>> Since you had better data service that has become degraded, >>>>>>>>> something >>>>>>>>> is clearly wrong somewhere. >>>>>>>> Not wrong. Different. He should force a V34+ connection and see if >>>>>>>> that behaves any better - but he doesn't listen to advice. >>>>>>>> >>>>>>>> Most likely one of his neighbours has moved to ADSL and the >>>>>>>> engineers have pinched his real copper circuit for that. >>>>>>>> Multiplexed local lines do not carry 56k signals at all well. The >>>>>>>> older analogue technology modems are a bit more robust in that >>>>>>>> environment. >>>>>>>> >>>>>>>> Regards, >>>>>>>> Martin Brown >>>>>>> Well,now if i KNEW how to force V34+ i would try. >>>>>> You should pay more attention to the postings in this thread and >>>>>> also ask on comp.modems and/or us.telecom or whatever it is called. >>>>>> They will know where you can dial into for a DIY line bandwidth >>>>>> test. Assuming that end users are allowed to do such things in "the >>>>>> land of the free". >>>>>> >>>>>> You might find a prehistoric early 56k UK FAQ helpful in trying to >>>>>> configure your modem to work retro style. >>>>>> >>>>>> http://www.pierrot.demon.co.uk/faq/dtm.faq >>>>>> >>>>>> (it is well out of date and UK based but still has good hints) >>>>>> >>>>>> Regards, >>>>>> Martin Brown >>>>> I have that UK reference and it is interesting and a bit informative. >>>>> I have TerraTerm Pro but i cannot use it with my ISP to do any >>>>> testing. >>>>> If i ATDTetc in, that works and see the prompt for username but +++ >>>>> does not escape to modem; if i am online like now, TerraTerm barfs. >>>>> So _that_ type of testing is out unless there is another number or >>>>> alternate to try. >>>>> One of the suggested tests was with >>>>> http://www.whichvoip.com/voip/speed_test/ppspeed.html and jitter was >>>>> 610mSec, packet loss of 0%, MOS score (whatever that is) of 2.9, >>>>> download speed 26.2K, upload speed of 21.5k and QOS at 92%. >>>>> Measured loop current 35mA, different US Robotics modem acts the same. >>>> OK. It seems that TerraTerm Pro is part of the problem. XP comes with >>>> a properly primitive terminal program though. You might try that. >>> Do not use XP, but maybe a similar prog is available with Win98SE; >>> will look for it. >>> Thanks. >> Found HyperTerm for Win98SE, it seemed to be installed but did not work. >> So..uninstall, reboot, install and it works.. >> .. sort-of. >> ATDT972-231-0633 >> (wait a bit) >> +++ >> AT%L%Q >> ERROR >> AT&V1 >> ERROR >> AT&L >> ERROR >> ATO >> (am now back online with isp asking for username and password) >> So, STILL cannot get info! >> What next? > > OK i started here: > > Google: "at command set" Which finds many things with these being on the > first page > > http://en.wikipedia.org/wiki/Hayes_command_set > http://nemesis.lonestar.org/reference/telecom/modems/at/plain-at.html > http://docs.kde.org/development/en/kdenetwork/kppp/appendix-hayes-commands.html > > Each one has links to further material. > > So you may want to add some more initialization commands before the dial > command. Notably adjusting the S37 register, some N, V, and maybe W > command; possibly starting with ATZ by itself. Of course you may wish to > look at the results of some I commands as well. For controlling > connection speed it should be done before the dial command. > > HTH Attached are two text (capture) files of tests i have done; i purposely used lower case so my commands via modem would stand out from modem responses. I have the USR CD and it gives the AT command set for their modem(s). Other than the possibility of the Xn command, i see no way to set data rate. Please review those files and advise what i should try next. ** Called "wonderful" "helpful" Qwest about connection problem. The extensive phone line testing was done in Apr 2009 with complete bill of health including almost no noise; that is when the tech said that a stinger had (note tense) been installed. The idiot at Qwest maintains there is no record of that, there is no way to determine that, and that nobody there knows what i am talking about (!!). The very same idiot maintains that i can communicate at _any_ data rate even above 1M (!!) and to call my ISP about the problem.
From: denali on 30 Apr 2010 18:38 On Apr 29, 1:47 pm, "Michael A. Terrell" <mike.terr...(a)earthlink.net> wrote: > Martin Brown wrote: > > > Michael A. Terrell wrote: > > > Martin Brown wrote: > > >> Michael A. Terrell wrote: > > >>> Martin Brown wrote: > > >>>> denali wrote: > > >>>>> On Apr 27, 12:08 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk> > > >>>>> wrote: > > >>>>>> denali wrote: > > >>>>>>> FYI, RE: JB's post.. leased line parameters are in no way applicable > > >>>>>>> to switched services. Forget about 3002 channels, etc. > > >>>>>>> Since you had better data service that has become degraded, something > > >>>>>>> is clearly wrong somewhere. > > >>>>>> Not wrong. Different. He should force a V34+ connection and see if that > > >>>>>> behaves any better - but he doesn't listen to advice. > > > >>>>>> Most likely one of his neighbours has moved to ADSL and the engineers > > >>>>>> have pinched his real copper circuit for that. Multiplexed local lines > > >>>>>> do not carry 56k signals at all well. The older analogue technology > > >>>>>> modems are a bit more robust in that environment. > > > >>>>>> Regards, > > >>>>>> Martin Brown > > >>>>> Your 56k comment is correct, but the point here is that he can't even > > >>>>> to 28.8, which narrows the likely problem/solution. Nothing is gained > > >>>>> by considering your point. > > > >>>>> D > > >>>> The telco frees up a real copper circuit for a higher value customer, > > >>>> and puts the cheapskates with basic phone only onto shared multiplexed > > >>>> lines. That destroys 56k and derivatives functioning at anything like > > >>>> full speed. V34+ will work better if the problem is as I describe. > > > >>> Real copper? A lot of the US has gone to Fiber optics to within a > > >>> mile or two of your home. I haven't seen much copper in Florida for > > >>> close to 20 years, except for the 'last mile'. > > >> The guy clearly lives in the boonies and doesn't have two pennies to rub > > >> together. It is entirely reasonable to assume that their local phone > > >> system is antique and decrepit. The "fault" he describes is identical to > > >> the problems people on multiplexed voice only lines experienced when 56k > > >> technology was rolled out. That is why I referred him to that old FAQ. > > > >> Most places in the UK are fibre up to the local exchange, but the last > > >> few miles is copper. Utilities are fighting tooth and nail in rural > > >> areas to avoid putting in any extra copper. That means as lines fail and > > >> more and more people get ADSL the remaining few on voice only lines are > > >> multiplexed in a black box somewhere between the exchange and their > > >> home. Answers.com has a description of the technology at about the right > > >> level for the OP to understand. > > > >>http://www.answers.com/topic/pair-gain > > > > Pair Gain isn't cheap in the US. Copper from the house to the CO > > > Pair gain is a heck of a lot cheaper than running new cables to the > > exchange in sparsely populated rural areas (which the US has a lot of). > > > > started disappearing over 25 years ago in the US. My first encounter was > > > when the phone company ripped out a leased pair between a fire station & > > > their siren at a paper mill a half mile away. That caused a mad > > > If you had a leased line from the telco then they have to provide a > > functionally equivalent replacement service over a virtual circuit. What > > you say does not make sense. > > It's simple. They were using it as a simple low voltage, current > limited remote switch which wasn't guaranteed by the contract, but the > phone company knew it was there and let them get away with it for > decades. Prior to that the dispatcher had to call the factory to have > the siren activated by an employee. A leased line was still available, > but was no longer a direct copper path between the two buildings. > Technology moves on, and old equipment is retired as it happens. Since > a lot of small departments had to move to radio control, the county set > up a county wide control system so they could set off the siren > directly. the could chose a single station, a small group, or in a > disaster, every station in the county. > > > I don't see what the problem is. The end > > user never knows what the details of the local exchange technology is. > > > Or are you saying that some cowboys from the fire service way back when > > piggybacked a siren connection into telco circuit trunking and telco > > snipped the cables when the upgraded to fibre optics? > > Fiber to the premise in the '80s? Dream on! > > > > scramble to convert it (and others) to remote control by VHF radio. > > > That took over $1000 out of the volunteer fire department's budget. > > > Why could you not continue with telco leased line service? > > It was no longer compatible with a simple SPST wall mounted switch > across the line. > Telco's, USWEST/QWEST included, running out of inter-office copper, had to "grandfather" the metallic 0-15 DC signal channel and discontinued the offering. It was replaced by voice-grade signal channel, and the customer had to provide their own tone hardware. Later, customers were advised of a date on which even the grandfathered channels would be discontinued.
From: denali on 30 Apr 2010 18:45 On Apr 30, 12:59 am, Martin Brown <|||newspam...(a)nezumi.demon.co.uk> wrote: > Michael A. Terrell wrote: > > Martin Brown wrote: > >> Michael A. Terrell wrote: > >>> started disappearing over 25 years ago in the US. My first encounter was > >>> when the phone company ripped out a leased pair between a fire station & > >>> their siren at a paper mill a half mile away. That caused a mad > >> If you had a leased line from the telco then they have to provide a > >> functionally equivalent replacement service over a virtual circuit. What > >> you say does not make sense. > > > It's simple. They were using it as a simple low voltage, current > > limited remote switch which wasn't guaranteed by the contract, but the > > Then the phone company was entirely within their rights to snip it. > > > > > > > phone company knew it was there and let them get away with it for > > decades. Prior to that the dispatcher had to call the factory to have > > the siren activated by an employee. A leased line was still available, > > but was no longer a direct copper path between the two buildings. > > Technology moves on, and old equipment is retired as it happens. Since > > a lot of small departments had to move to radio control, the county set > > up a county wide control system so they could set off the siren > > directly. the could chose a single station, a small group, or in a > > disaster, every station in the county. > > >> I don't see what the problem is. The end > >> user never knows what the details of the local exchange technology is. > > >> Or are you saying that some cowboys from the fire service way back when > >> piggybacked a siren connection into telco circuit trunking and telco > >> snipped the cables when the upgraded to fibre optics? > > > Fiber to the premise in the '80s? Dream on! > > That seemed to be what you were claiming. We had internal fibre links on > campus as a part of one of the earliest WANs in the early 1980's. > > >>> scramble to convert it (and others) to remote control by VHF radio. > >>> That took over $1000 out of the volunteer fire department's budget. > >> Why could you not continue with telco leased line service? > > > It was no longer compatible with a simple SPST wall mounted switch > > across the line. > > So you were using a spurious feature that was not supported by the > telco. Pretty much as I suspected a prehistoric jerry rigged cowboy > wiring solution that they did not guarantee to support. > > Regards, > Martin Brown You're overly critical. The DC signal channel was an offered service throughout the Bell System. I probably even have a copy of the Technical Publication somewhere.
From: denali on 30 Apr 2010 19:04
On Apr 30, 12:28 pm, Robert Baer <robertb...(a)localnet.com> wrote: > JosephKK wrote: > > On Wed, 28 Apr 2010 16:45:04 -0700, Robert Baer <robertb...(a)localnet.com> > > wrote: > (snip) > ** > Called "wonderful" "helpful" Qwest about connection problem. > The extensive phone line testing was done in Apr 2009 with complete > bill of health including almost no noise; that is when the tech said > that a stinger had (note tense) been installed. > The idiot at Qwest maintains there is no record of that, there is no > way to determine that, and that nobody there knows what i am talking > about (!!). > The very same idiot maintains that i can communicate at _any_ data > rate even above 1M (!!) and to call my ISP about the problem. > (snip) You're right, the person appears to be oblivious. There is a very simple way for that phone answerer to obtain all the details of the facility assigned to your phone line. It's called, appropriate enough, the Line Assignment record. I can't call them about this for you, because I am not your designated representative. If you have a way to conference me onto a call with them, however, I can talk with them. But it might cost you a beer at the nearest McMenamins. |