[Crew] UK PSTN In-band signaling??!??!?!

Re-LoaD reload at brum2600.net
Tue Sep 5 11:51:21 BST 2006

Daac wrote:
> Cheers Re-Load:)
> Point one was not ironic, my question really wasn't
> about blue boxing. 
> Some expansion:
> Penny-sweets to the boys and girls who recognised 852
> hz+1633 hz as being the c-tone on the extended dtmf
> pad! My question was prompted by Mab's fantastic paper
> on CALEA countermeasures. It seems CALEA hardware
> makes extensive use of in-band signaling, including
> the use of the c-tone to denote call termination. The
> trick is that you can inject a c-tone which is outside
> the parameters(volume and/or freq) accepted by the
> switch in your local exchange, but within the those of
> the CALEA device. Thus the switch doesn't disconnect
> you, but the CALEA device thinks the call is over.
> Very nice. 

And for those who wish to play see attached :)

> Any comments most gratefully recieved.
> -Karamoon
> ps. Is the Fed Test that thing where you have to keep
> whistling while your legs are forced apart by the
> school bully? :)

More a long the lines of you keep buying the beer until we just can't 
take it any more and stop call you a FED :D~


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