Wawina Township, MN is home to the Northern Telephone
Company of Minnesota. What makes this place unique is that it is the
smallest telphone company in the United States, serving less than 40
total customers. It is owned by Bob Riddell.
What also made this place unique is that it was also
the last place in the continential United States to use a trunking
system (inter-office circuits) that was called "N2 Carrier", an analog
system that utilized Multi-Frequency (MF) tones and the infamous 2600 Hz
control tone for answer supervision and idle trunk condition.
15, 2006, the analog N2 carrier was replaced with digital T1 carrier,
and with it the use of MF signalling.
following page are examples of sounds & recordings collected in 1999,
2002 & 2006.
All files are in MP3
format. Click on a link to listen.
Intercept - 1999 & 2002
The following are examples of funny
centralized intercept recordings from September 1999 & February 2002. These were homemade
recordings by Bob Rindell or Shane Young.
Please ask your mother to help you. (Shane Young)
Check the address and write them a letter. (Bob Rindell)
Ask the operator to help you, but she'll tell you the same thing.
An update to #1 above, with SIT tones. (Shane Young)
Assembled from a "borrowed" recording. (Shane Young)
Assembled from a "borrowed" recording. Note it sounds like an old
Bell System automated intercept recording from the 1980s. (Shane
Sometime around 2006, an automated
intercept recording system was installed. Here are some examples.
Original automated intercept from March 2006 (218-488-0000). Notice
the 2600 Hz answer supervision chirp at the end of the recording.
Updated automated intercept from April 2006. This one adds "Ask your
mother to help you," similar to that of the 1999 centralized
intercept above. This recording did not supervise.
Same as #2 above, but with lots of background noise (N2 carrier
combined with T1 carrier on same cable pair). (June 2006)
This one just gives out the phone number (in this case,
218-488-1300) and a 2600 Hz supervision chirp. (May 2006)
This one gives out an Internet IP address. (June 2006)
Time of Day
Time of Day recording (488-TIME). Notice the use of a
"bong" tone, similar to that of AT&T. This does NOT give answer
supervision. (February 2002)
Time of Day recording. The "bong" tone has been removed.
This version does give answer supervision and
a 2600 Hz chirp when it disconnects. (May 2006)
Analog hiss from the N2 carrier system. You need to turn up your
volume VERY loud to hear it. (May 2006)
Analog hiss from the N2 carrier system combined with the T1 digital
carrier noise. (June 2006)
Wake Up Call
A system for initiating a wake-up call. (June 2006)
Mental Health Hotline
A funny joke that has been used for answering machines for a while.
This one does supervise and gives a 2600 Hz chirp when it completes.
A supervision test for the Redcom MDX-384 switch that is in use in
Wawina. Notice the 2600 Hz chirps and high tone.
(218) 488-9108 and 9109 are the two sides of a conversation loop.
When the loop is idle, you receive a very loud miliwatt tone. When
the loop is complete (meaning there is a called party on both ends),
you can have a conversation. This is an example of how the loop
worked with a "conversation with myself."
The N2 carrier system that the Northern
Telephone Company of Minnesota used (supplied by Qwest from the
Duluth, MN tandem) was 2600 Hz controlled and used Multi-Frequency
(MF) tones. Normally, you would need to use "KP" (Key Pulse) before
the digits and "ST" (Start) to terminate the MF string. But in this
case, they were optional, as you can tell from these recordings. These
were made on MCI, because AT&T mutes forward voice path until the
called party answers. However, there is a 2 minute time limit on
unsupervised calls, and that's when you hear the reorder that ends
these recordings. The "Blue Box" tones were provided by an old DOS
program "Blue.exe" on my laptop, while my desktop recorded the call.
Box #1 (Streaming MP3)
An example of Blue Boxing. Dialing various numbers with the 488
prefix. Notice it takes 7 digits and you can't dial out of the
system, only numbers within the switch.
Box #2 (Streaming MP3)
Another example of Blue Boxing. Dialing various numbers with the 488
prefix. Notice it takes only 7 digits (no KP, no ST) and you can't dial out of the
system, only numbers within the switch.
Goodbye to N2
Supposedly this was the last N2 carrier
system in the continential United States. Shane Young very graciously
set up a voice mail system where people could leave their last
respects to the N2 carrier system. Notice the 2600 Hz chirps at the
end of each call. Notable people who left messages included old
"phreaks" such as Captain Crunch (John Draper), Mark & Al Bernay,
Joybubbles (born Joe Engressia) and many many other people.
By the cutover to T1 carrier on June 15,
2006, over 2 hours were recorded on the voice mail system. In order to
share these with you, I have divided the recordings into 8 parts at 15
minutes each (part 8 is 17 minutes). All of these were retrieved off
the voice mail system on June 16, 2006.
1 (Streaming MP3)
2 (Streaming MP3)
3 (Streaming MP3)
4 (Streaming MP3)
5 (Streaming MP3)
6 (Streaming MP3)
7 (Streaming MP3)
8 (Streaming MP3)
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Page last modified December 20, 2008
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