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whixrr

Single frequency phreaking tones

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If anyone knows any single tone phreaking frequencies, please post them below.

 

(examples)

 

2600hz-seized trunks back in the day

1100hz-Fax presence  (yet to be explored)

Edited by whixrr
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The AC9 UK trunk signalling system used 2280Hz for line supervision and tone dialing. The trunk was cleared by sending 2280Hz for 1 second. After the "clear forward" tone and a 1-second pause, the trunk was re-seized by sending an additional 95ms of 2280Hz. After an additional 1 second delay, the dial pulses were then sent just like US 2600Hz but with 2280Hz - 66ms of tone, followed by 34ms of silence for each pulse, with a 500ms silence between digits.

 

The older AC1 UK trunk signalling system used a two-tone system:

 

 

The line was cleared with 2 seconds of 750Hz, followed immediately by 800ms of 600Hz (no delay between the two tones, followed by 2 seconds of silence. Then, the line was re-seized with 100ms of 750Hz, followed by 3 seconds of silence. Then dial pulses were sent with 750Hz, on for 66ms, off for 34ms. Timing between digits was a full 1 second.

 

CCITT #4 used two single tones (2400Hz and 2040Hz) for clearing the line, re-seizing, and sending 4-bit binary codes for the digits and other routing codes. Details are a bit too complicated to describe here. My Arduino blue box documentation has a table with the particulars: http://www.instructables.com/files/orig/FI5/VREN/I2AQTKSE/FI5VRENI2AQTKSE.zip

 

D.

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Echo cancelers, and on the networks that have them, comfort noise generators will respond to 2100 hertz. Most of the time, the echo cancelers will come back on after a second of silence. The comfort noise generators will wait a little longer (or just ignore it entirely), but unfortunately, they really do come back.

 

Basically, 2100 hertz is the handshake tone of most higher baud rate modems. When echo cancellation is enabled, you can't always send the same frequency in both directions, so that limits the amount of data you can transmit. So they drop out to accommodate that, and the modems provide their own echo cancellation.

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