Mailinglist Archive: opensuse (1108 mails)

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Re: [opensuse] Fax vulnerability
On 2018-08-17 03:42, James Knott wrote:
On 08/16/2018 09:00 PM, David C. Rankin wrote:
I have my bluebox ready....

That might not get you much these days.  Back when the phone network was
analog, operators had key pads with 16 buttons, instead of the 12 (10 on
older phones) on regular telephones.  Those extra buttons were what the
operator used to control calling.  These days, with the digital network,
Signalling System 7 (SS7) is used to control the network.  The push
buttons are converted to SS7 at the first opportunity, at the exchange
with analog phones, and touch tones, but as early as the phone on
digital (ISDN) connections.  So, these days those extra buttons are
useless when making a call.  Using touch tones is called in band
signalling, but SS7 uses a dedicated 64 Kb data channel, to carry the
signalling information.  This is known as out of band signalling.

AFAIK, SS7 is not used for signalling with the customer, but between
exchanges. At least, I never saw it. I believe ISDN used its own
signalling, Q.931 says wikipedia.

And no, there was no security involved in the SS7 code: instead, the
transmission channel has to be secured.

Cheers / Saludos,

Carlos E. R.
(from 42.3 x86_64 "Malachite" at Telcontar)

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