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Message Digest
Volume 28 : Issue 297 : "text" Format
Messages in this Issue:
Re: AT&T Wireless data congestion possibly self-inflicted
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Area code 533 assigned for personal communications services
Re: Comcast seeks NBC-U (continued)
Re: AT&T Wireless data congestion possibly self-inflicted
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Date: Wed, 28 Oct 2009 16:50:31 +1100
From: David Clayton <dcstar@NOSPAM.myrealbox.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: AT&T Wireless data congestion possibly self-inflicted
Message-ID: <pan.2009.10.28.05.50.28.843805@NOSPAM.myrealbox.com>
On Tue, 27 Oct 2009 18:25:26 -0700, hancock4 wrote:
> On Oct 27, 2:29 pm, "Jack Myers" <jmy...@n6wuz.net> wrote:
>
>> Who wants to move forward into the past by using positive end-to-end
>> control, more small buffers (for improved end-to-end latency), and
>> request-to-send/clear-to-send hardware signalling at the end-user
>> interface?
>
> Could this be explained in layman's terms?
.........
> What is "end to end latency" so that we want to improve it?
>
Pre-empting an anticipated avalanche of replies, "end to end latency" is
the time it takes whatever you send at one end of a link to get to the
other end.
In digital circuits this is the sum of the physical time it takes to send
one data bit across the path AND the time it takes to assemble ALL of the
bits you want to send in each packet that is sent as an individual entity
across the path (referring to connections with a packet switched
component, of course).
Phone users will be familiar with the latency of geosynchronous satellite
circuits compared to land line connections (either local or international)
and the general rule for any real-time communication (like voice) is the
less latency the better.
In data connections, smaller packets reduce overall latency but at the
cost of inefficiently using the available data bandwidth compared to large
(which means higher latency) packets, so any data carrier will try to
squeeze as much efficiency out a highly loaded link by using as large a
packet size as possible.
It's a compromise, the ATM packet size is a classic example of being
bigger than what the voice people wanted but smaller than the data
people's preferences, so ATM packets aren't the most efficient things for
data carriage but work well enough and could well have been smaller for
less voice latency but they still work well enough.....
If packets (of any sort) end up being buffered, then the time it takes to
clear the buffer just adds to the overall latency as well because it adds
to the physical time in the overall connection/circuit.
--
Regards, David.
David Clayton
Melbourne, Victoria, Australia.
Knowledge is a measure of how many answers you have, intelligence is a
measure of how many questions you have.
Date: Wed, 28 Oct 2009 06:41:16 -0700 (PDT)
From: hancock4@bbs.cpcn.com
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <0f452836-f801-4e20-ac1a-56c76d095ea7@p35g2000yqh.googlegroups.com>
On Oct 27, 8:31 pm, "Adam H. Kerman" <a...@chinet.com> wrote:
> Area code 500 is exhausted, and 533 has been assigned for personal
> communications services. I had no idea these featurs were so popular.
What are "personal communications services"?
Date: Wed, 28 Oct 2009 17:25:55 +0000 (UTC)
From: "Adam H. Kerman" <ahk@chinet.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <hc9ur3$pru$2@news.albasani.net>
hancock4@bbs.cpcn.com wrote:
>On Oct 27, 8:31 pm, "Adam H. Kerman" <a...@chinet.com> wrote:
>> Area code 500 is exhausted, and 533 has been assigned for personal
>> communications services. I had no idea these featurs were so
>> popular.
> What are "personal communications services"?
I don't know what these numbers are used for today. I've never seen a
phone company marketing the service.
It was my understanding that 500 was a non-geographical area code that
was originally internal to a long distance provider. A subscriber had
this number pointed to a particular phone, that could be anywhere in
the country.
To call the subscriber, one had to know what long distance company he
subscribed to if the PIC had to be dialed. One wouldn't know how the
call was distance rated in advance as it was based on the location of
the terminating number, which wouldn't be known to the caller. I
assume if the subscriber and the caller were both subscribed to the
same long distance provider that the calls were charged at the
caller's long distance rates, but if the caller was forced to use
casual calling rates, the call would be absurdly expensive.
At some point, this was changed to an entirely different type of
service. I have no idea what it is today, or how to subscribe to it,
or why I would want to subscribe to it. And I'm totally mystified as
to how a service that no one uses managed to run out of prefixes.
Date: Wed, 28 Oct 2009 13:03:22 -0700
From: Thad Floryan <thad@thadlabs.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <4AE8A38A.9010700@thadlabs.com>
On 10/28/2009 10:25 AM, Adam H. Kerman wrote:
> hancock4@bbs.cpcn.com wrote:
>> On Oct 27, 8:31 pm, "Adam H. Kerman" <a...@chinet.com> wrote:
>
>>> Area code 500 is exhausted, and 533 has been assigned for personal
>>> communications services. I had no idea these featurs were so
>>> popular.
> [...]
> It was my understanding that 500 was a non-geographical area code that
> was originally internal to a long distance provider. A subscriber had
> this number pointed to a particular phone, that could be anywhere in
> the country.
> [...]
> At some point, this was changed to an entirely different type of
> service. I have no idea what it is today, or how to subscribe to it,
> or why I would want to subscribe to it. And I'm totally mystified as
> to how a service that no one uses managed to run out of prefixes.
Curious, I entered "500-123-4567" to Google.
The number of Google "hits" is reasonably large. Here's one reasonably
good explanation of "500" from
http://www.lincmad.com/nongeographic.html:
Personal Communications Services (a.k.a. "the Other PCS") in this
context refers not to cellular telephones, but rather to so-called
"follow-me" numbers. The idea was to have a single number, say (500)
123-4567, that you could program to ring your home phone from 6 to 10
p.m., go directly to voicemail at night, and ring your desk at work
during the day. The number could also have some sort of response menu,
along the lines of "press 1 for voicemail, 2 for fax, 3 for
cellphone." Some implementations also allowed the same 500 number to
be used for caller-pays or called-party-pays: dialing 1-500-xxx-xxxx,
the caller would pay the cost of the call, but dialing 0-500-xxx-xxxx,
the caller could enter a 4-digit PIN to charge the call to the owner
of the number. However, in spite of some attempts to keep telesleaze
out of the 500 number space, some unscrupulous operators exploited a
feature that allowed 500 numbers to forward internationally, with the
additional charge borne by the caller with only a "press 1 to accept"
warning, if that.
The 533 code was assigned as an expansion of 500, although no one is
quite sure why it was assigned, since demand for 500 numbers has been
steadily decreasing. The assignment was subsequently withdrawn. As of
2008-05-23, NANPA projects activating 533 in the second half of 2009;
however, 533 has been "within 6 to 18 months" for several years
now. Bottom line: I'll believe it when I see it. In particular, as of
2008-01-01, there were 79 available (533) prefixes to be assigned. In
the first 5 months of 2008, 43 of those were handed out; however, 171
other (533) prefixes were returned or reclaimed, leaving 207 available
for assignment. That's not a very intimidating demand curve from where
I sit.
Date: 28 Oct 2009 20:02:30 -0000
From: John Levine <johnl@iecc.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <20091028200230.5070.qmail@simone.iecc.com>
>It was my understanding that 500 was a non-geographical area code that
>was originally internal to a long distance provider. A subscriber had
>this number pointed to a particular phone, that could be anywhere in
>the country.
No, that's 700 numbers. The idea of 500 numbers was that they were
intended for personal follow-me service and the like, charged to the
caller.
Since you can't predict how much a 500 number will cost, not unlike
a 900 number, I figured they would fail. From the little I can see
on Google, I get the impression that the 500 numbers in use don't
cost anything to the caller.
R's,
John
Date: Wed, 28 Oct 2009 23:55:09 +0000 (UTC)
From: "Adam H. Kerman" <ahk@chinet.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <hcalks$th8$1@news.albasani.net>
John Levine <johnl@iecc.com> wrote:
> "Adam H. Kerman" <ahk@chinet.com> wrote:
>> It was my understanding that 500 was a non-geographical area code
>> that was originally internal to a long distance provider. A
>> subscriber had this number pointed to a particular phone, that
>> could be anywhere in the country.
Correction: These can point to numbers outside the country. Your
telephone bill might contain a not so nice surprise!
> No, that's 700 numbers. The idea of 500 numbers was that they were
> intended for personal follow-me service and the like, charged to the
> caller.
So these aren't sold by long-distance providers? Is the 500 number
limited to a particular provider or can they be ported?
> Since you can't predict how much a 500 number will cost, not unlike
> a 900 number, I figured they would fail. From the little I can see
> on Google, I get the impression that the 500 numbers in use don't
> cost anything to the caller.
I don't get it, then.
Date: Wed, 28 Oct 2009 14:05:49 -0500
From: John Mayson <john@mayson.us>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <6645152a0910281205y72fec88bq7323098e2b442d13@mail.gmail.com>
On Wed, Oct 28, 2009 at 8:41 AM, <hancock4@bbs.cpcn.com> wrote:
> On Oct 27, 8:31Â pm, "Adam H. Kerman" <a...@chinet.com> wrote:
>> Area code 500 is exhausted, and 533 has been assigned for personal
>> communications services. I had no idea these featurs were so
>> popular.
>
> What are "personal communications services"?
Good questions; I'm still not sure I understand it.
http://en.wikipedia.org/wiki/Area_code_500
http://en.wikipedia.org/wiki/Personal_Communications_Service_(NANP)
John
--
John Mayson <john@mayson.us>
Austin, Texas, USA
Date: 28 Oct 2009 15:08:21 -0000
From: John Levine <johnl@iecc.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Area code 533 assigned for personal communications services
Message-ID: <20091028150821.6241.qmail@simone.iecc.com>
In article <hc83cq$5qr$1@news.albasani.net> you write:
>Area code 500 is exhausted, and 533 has been assigned for personal
>communications services. I had no idea these featurs were so popular.
>
>Is there any chance that huge chunks of numbering space were wasted and
>should have been reclaimed first?
If you look at the assignment list, which is by NXX, they're almost
all assigned to Verizon Wireless and Cingular/AT&T, and the first
chunk of 533 is to Cingular. I presume they wouldn't be asking for
more if they couldn't show NANPA that they were in use, but I've never
seen a 500 number in use, either.
R's,
John
Date: Wed, 28 Oct 2009 11:04:08 -0700 (PDT)
From: Neal McLain <nmclain@annsgarden.com>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: Comcast seeks NBC-U (continued)
Message-ID: <f418d105-c902-4505-badd-259091f5e474@x6g2000prc.googlegroups.com>
On Oct 27, 5:44 pm, "Geoffrey Welsh" <gwe...@spamcop.net> wrote:
> Do advertising limits even make sense in the day of 24/7 shopping channels?
> .
The saga continues...
Vivendi CEO says IPO an option for NBC Universal
Tue Oct 27, 2009 3:08pm EDT
WATFORD, England (Reuters) - NBC Universal could be floated on the
stock market if France's Vivendi decides to sell its 20 percent stake
in the group majority-owned by General Electric, Vivendi's chief
executive said on Tuesday.
http://www.reuters.com/article/industryNews/idUSTRE59Q4ET20091027
Neal McLain
Date: Wed, 28 Oct 2009 10:12:23 -0700
From: "Jack Myers" <jmyers@n6wuz.net>
To: redacted@invalid.telecom.csail.mit.edu
Subject: Re: AT&T Wireless data congestion possibly self-inflicted
Message-ID: <nkamr6-ijv.ln1@n6wuz.net>
hancock4@bbs.cpcn.com wrote:
> On Oct 27, 2:29?pm, "Jack Myers" <jmy...@n6wuz.net> wrote:
> > Who wants to move forward into the past by using positive
> > end-to-end control, more small buffers (for improved end-to-end
> > latency), and request-to-send/clear-to-send hardware signalling at
> > the end-user interface?
> Could this be explained in layman's terms?
I suspect a possible troll since your postings here indicate you
really do know this stuff.
> That is, what is "end to end control" and the difference between
> "positive" and non-positive control of it?
The Internet Protocol (IP) is a "best efforts" transport layer. Dump
bits in at one end and accept the possibility that some of the bits
will get lost along the way. The bits are important--why else would we
pay the big bucks to send and receive them--so we are willing to pay
in terms of time, throughput, or bandwidth to detect/correct these
transmission errors. Congestion, which is due to instantaneous peaks
and valleys in the aggregate traffic flow, causes some of the data
loss. Buffering helps to smooth out the flow. It reduces data loss
(reduces retransmission requests, improves throughput) at the expense
of possibly increasing delays (network latency). The complaints were
about variable delays, and the best-efforts IP layer is the ultimate
cause. Some positive alternatives are reservations (like airline
seats) and access metering (like freeway on ramps.)
> Why is this considered "into the past"?
Some of the original data communications protocols, which have been
temporarily displaced by IP, had hardware or software reservation
schemes or access metering. It's a way for the network to signal its
status and capabilities back to the end users.
> Is this stuff good or bad?
It's just engineering. There's no intrinsic good or bad here.
> What is "request-to-send/clear-to-send hardware signalling" and if
> not accomplished as described, what are other options for doing so,
> and are they better or worse?
RTS analogy: A car stops over the sensor loop on a freeway on ramp.
CTS analogy: The traffic metering light turns green.
Access metering advantage: Throughput is optimized, delays minimized,
fewer cars "lost" in transit.
Access metering disadvantage: Neutrality suffers because the "haves"
who are already on the freeway have an advantage over the "have nots"
who are queued up at the entrance or taking a longer slower route.
Conclusion: something more than simple metering is required [to
optimize] transit [times].
Is my frustration with the academic systems engineers on a recent
networking project coming through yet?
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End of The Telecom digest (10 messages)
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