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Message Digest
Volume 28 : Issue 120 : "text" Format
Messages in this Issue:
Re: size a major consideration in mobile phone sets
Re: T-Mobile glorifies vandalism?
Re: Notifying subscribers that CLID blocking won't block ANI?
AT&T to discontinue CallVantage voip service
Re: AT&T to discontinue CallVantage voip service
Re: AT&T to discontinue CallVantage voip service
====== 27 years of TELECOM Digest -- Founded August 21, 1981 ======
Telecom and VOIP (Voice over Internet Protocol) Digest for the
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against crime. Geoffrey Welsh
===========================
See the bottom of this issue for subscription and archive details
and the name of our lawyer, and other stuff of interest.
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Date: Thu, 30 Apr 2009 23:47:10 -0700
From: Richard <rng@richbonnie.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: size a major consideration in mobile phone sets
Message-ID: <d6akv4dfp78hh48q1kgds1jqlj2dn2uijb@4ax.com>
On Thu, 30 Apr 2009 15:00:05 -0400 (EDT), David Lesher
<wb8foz@panix.com> wrote:
> There is also flexible [and I use the term loosely;
>"not rigid" might be better....] waveguide.
>From the 1950's to about 1990, AT&T's long-haul
(i.e.trans-continental) microwave routes used horn reflector antennas
http://long-lines.net/tech-equip/radio/BSP402421100/p03.html
fed by a 2.812 inch diameter circular waveguide
http://long-lines.net/tech-equip/radio/WE-waveguide/WEWP-4.html
This waveguide shape and size was chosen for its extremely low loss
(0.38 dB/100 feet at 3.8 GHz). Being symmetrical axially, it could
support two orthoganal polarizations.
One drawback of this waveguide was that it supported more than one
mode: 2 or 3 modes in the 3.7 to 4.2 GHz band (depending on
frequency), and 6 modes in the 5.925 to 6.425 GHz band. Any
non-uniformity, and also the transitions from square guide (used by
the frequency and polarization combining networks) at the base of the
tower to the circular guide, and from the circular guide to the
antenna, would convert some of the energy to and from the dominant
mode to the higher-order modes. Each mode traveled at a different
velocity, so when energy from a higher-order mode reconverted to
dominant, an echo resulted. The towers ranged up to 250 feet high,
and thus the echos had appreciable time delays.
One of the worst offenders was an 8-foot length of flexible circular
waveguide which connected the top of the vertical waveguide run to the
feedhorn of the antenna, to allow the antenna to be pointed in
elevation. Eventually, we had to replace each pieces of flex guide
with a piece of rigid guide especially bent to shape, on site, to fit
between the antenna and the vertical waveguide run. First, the crew
measured the relative positions of the two flanges. Then an 8-foot
piece of rigid guide was packed with sand to keep it from buckling,
and put onto a machine which put a gradual bend in the guide.
***** Moderator's Note *****
You bring back a memory: my father was a pluber, and he used to bend
pipe that way when he had to have a non-standard angle. I used to hold
the torch, and he'd heat a copper pipe to orange, then use a lalley
column to form the bend: every so often, there'd be some moisture in
the sand, which would flash-burn any human flesh within a foot of the
ends.
BTW, please explain what "Mode" means in this context. TIA.
Bill Horne
Temporary Moderator
------------------------------
Date: Fri, 01 May 2009 01:41:04 -0700
From: Sam Spade <sam@coldmail.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: T-Mobile glorifies vandalism?
Message-ID: <AAyKl.4121$3k7.2935@newsfe17.iad>
hancock4@bbs.cpcn.com wrote:
> On Apr 30, 3:16 pm, Sam Spade <s...@coldmail.com> wrote:
>
>
>>As I recall the first in-service No 1 ESS was somewhere in New Jersey.
>>That was after the Morris trial.
>
>
> I had to look it up: Succasunna. A small town near Morristown.
>
> They learned a lot from that, too. Later 'boxes' had better
> electronics and offered faster processing in a much smaller
> footprint. They also tinkered with how much was done by the CPU and
> how much was done by peripheral processors.
>
> I've heard suggested that early ESS did not do too well when
> overloaded with calls; apparently instead of just giving slow dial
> tone as capacity permitted, they couldn't even respond, perhaps
> because all the traffic handling overwhelmed it so that nothing could
> be done and switch essentially froze up.
>
The 1A represented a major improvement. Pac Bell limited the traffic on
their No. 1 models. Once they got the 1A in service they realized it
wouldn't fail handling multiple office codes. They then, and I presume
the other BOCs, undertook a project to upgrade No. 1s to 1As.
------------------------------
Date: Thu, 30 Apr 2009 12:53:25 -0700
From: Steven Lichter <diespammers@ikillspammers.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Notifying subscribers that CLID blocking won't block ANI?
Message-ID: <wenKl.17158$8_3.1861@flpi147.ffdc.sbc.com>
Adam H. Kerman wrote:
> hancock4@bbs.cpcn.com wrote:
>
>>> ***** Moderator's Note *****
>
>>> I don't think of the 800 number ANI tranmission as being "selfish".
>>> It's a system that predates caller id, and it has _never_ been hidden
>>> or secret. Those who pay for 800 numbers do so in accordance with the
>>> tariffs, and those tariffs are availalbe for anyone to read.
>
>>> What you're advocating is, and always will be, impossible: you can't
>>> protect consumers from their tendency to assume that there is such a
>>> thing as a free lunch. I'd say "The truth is out there", but that
>>> would imply that someone was trying to hide it. The facts are out
>>> there, and always have been for those who choose to seek them.
>
>> I have to respectfully disagree, although my post may have been worded
>> poorly. Allow me to rephrase it:
>
>> I think if someone dials the block code (1167?) then an 800 number,
>> they should get a recording saying their number cannnot be blocked for
>> 800 calls. I don't see that as being any burden to provide.
>
> I agree with Bill.
>
> The trouble with your suggestion is that, essentially, the phone company
> would have to refuse to route a call to an 800 number with per-call CLID
> blocking. You're forgetting about phone company services and equipment
> that implement CLID blocking on all calls, so it wouldn't be practical
> to implement this refusal. What would have have the caller do, dial the
> CLID unblock code before an 800 number to acknowledge to the system that
> he's aware of the notice?
>
> What if we put the calls through on behalf of a subscriber who blocks
> CLID on all calls? Do we make him suffer through that recorded
> announcement each and every time he places a call to an 800 number?
>
> Another thing to remember is that the code to block Caller ID isn't part
> of the call's routing instructions. Your local switch has no idea how to
> route a call to an 800 number. It must get instructions from a switch
> specific to 800 number routing. The CLID blocking code is simply
> ignored. I see no purpose to redesigning the system.
>
>> I also think that some companies who offer customers 800 service might
>> not want their customers to know about ANI--that is, they would be
>> happy if their customers were left in the dark and thought their
>> number was blocked when in fact it wasn't.
>
> Ok. But you haven't put the burden on that company, but the local switch
> to play a recording to educate the subscriber. You really want the local
> switch's record to explain the difference between Caller ID and ANI?
>
During 1999 and 2000 I was working on a project in Las Vegas; the CLEC
that supplied the dial tone to the hotel I was staying at did not pass
the CLID and for some reason there was no ANI; My best guess was they
were not passing SS7 data. I would dial the 800 number to reach the GTE
LD operator (Verizon), they did not see any number on their boards.
Because of this I was unable to call home because we had our phone set
to reject any phone without CID and there was no option on the hotel
phone to dial the unblock code. I found out who they were and it was
like talking to a wall; I was never able to get to a tech, they were
using a DMS switch. I was working on a Sprint project at that time so I
talked to the CO techs and NOC people. Nothing I did could get it
fixed. I finally started calling using a cell phone and not the calling
card that my company had given me, but those were the days before
calling plans with minutes.
--
The Only Good Spammer is a Dead one!! Have you hunted one down today?
(c) 2009 I Kill Spammers, Inc. A Rot In Hell Co.
------------------------------
Date: Fri, 1 May 2009 13:01:04 -0500
From: "George S Thurman" <gsthurman@aol.com (nospam)>
To: redacted@invalid.telecom.csail.mit.edu
Subject: AT&T to discontinue CallVantage voip service
Message-ID: <ANGKl.28899$YU2.3752@nlpi066.nbdc.sbc.com>
Just rec'd a letter from AT&T saying they are going [to] discontinue
[their] VOIP service, known as CallVantage. The letter was dated April
17, but an exact discontinuation date was not mentioned. I have tried
Vonage, but did not like the poor quality of some of the connections,
although I did like some of the features it had [which] CallVantage did
not. I will not go back there. Can someone recommend another VOIP
service?
George "Skipper" Thurman
------------------------------
Date: 1 May 2009 21:09:58 -0000
From: John Levine <johnl@iecc.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: AT&T to discontinue CallVantage voip service
Message-ID: <20090501210958.74983.qmail@simone.iecc.com>
> Can someone recommend another VOIP service?
I didn't like Vonage either, but I've been reasonably happy with Lingo,
the voip service from Primus Telecommunications, a largish international
long distance telco.
If interested, write me directly and I'll send you a coupon.
Regards,
John Levine, johnl@iecc.com, Primary Perpetrator of "The Internet for Dummies",
Information Superhighwayman wanna-be, http://www.johnlevine.com, ex-Mayor
"More Wiener schnitzel, please", said Tom, revealingly.
***** Moderator's Note *****
Is Vonage still losing money, or have they shown a profit yet?
Does Lingo require a separate router like Vonage does, or will it work
with a PC directly. Will Lingo operate directly with Asterisk?
Bill
"I will not share my lobster!" said Tom, shellfishly
Bill Horne
Temporary Moderator
------------------------------
Date: Fri, 01 May 2009 17:28:08 -0600
From: Robert Neville <dont@bother.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: AT&T to discontinue CallVantage voip service
Message-ID: <o01nv4lmu23si64tf3gd1iq80r4t22rfaq@4ax.com>
"George S Thurman" <gsthurman@aol.com (nospam)> wrote:
>Just rec'd a letter from AT&T saying they are going [to] discontinue
>[their] VOIP service, known as CallVantage. The letter was dated April
>17, but an exact discontinuation date was not mentioned. I have tried
>Vonage, but did not like the poor quality of some of the connections,
>although I did like some of the features it had [which] CallVantage did
>not. I will not go back there. Can someone recommend another VOIP
>service?
IIRC, AT&T was going to send out individual notifications as part of a rolling
shutdown between now and fall. You might keep in mind that all it takes to run a
VOIP service is a 386 computer, a phone line or two and some open source
software. Meaning that anyone can run a VOIP service out of their garage. If you
want to stick with VOIP, I'd only consider established companies like Packet8 or
Vonage.
In my experience, call quality issues from any company are usually related to
bandwidth constraints and jitter on the underlying connection and not with the
VOIP service.
***** Moderator's Note *****
Isn't that a bit like blaming poor line quality on old cable and dirty splices?
Bill Horne
Temporary Moderator
------------------------------
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End of The Telecom digest (6 messages)
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